diff --git a/Viewer/features/base.js b/Viewer/features/base.js
index 30ca7401..33e961d5 100755
--- a/Viewer/features/base.js
+++ b/Viewer/features/base.js
@@ -1806,9 +1806,19 @@ module.Crop = core.ImageGridFeatures.Feature({
 	tag: 'crop',
 	depends: [
 		'base',
+		//'cache',
 	],
 
 	actions: CropActions,
+
+	handlers: [
+		[[
+			'crop',
+			'uncrop',
+			'removeFromCrop',
+		],
+			'clearCache: "view(-.*)?" "*" -- Clear view cache'],
+	],
 })
 
 
diff --git a/Viewer/features/collections.js b/Viewer/features/collections.js
index 7140e666..2e3201b6 100755
--- a/Viewer/features/collections.js
+++ b/Viewer/features/collections.js
@@ -1779,6 +1779,13 @@ module.Collection = core.ImageGridFeatures.Feature({
 						// XXX
 					})
 			}],
+
+		// invalidate caches...
+		[[
+			'loadCollection',
+			'uncollect',
+		],
+			'clearCache: "view(-.*)?" "*" -- Clear view cache'],
 	],
 })
 
diff --git a/Viewer/features/core.js b/Viewer/features/core.js
index dc47e1df..e66a992a 100755
--- a/Viewer/features/core.js
+++ b/Viewer/features/core.js
@@ -1027,9 +1027,21 @@ module.Serialization = ImageGridFeatures.Feature({
 // Cache...
 	
 // XXX should this be in actions.js???
-// XXX should we invalidate the cache automatically???
-// XXX the cache can also be saved to localStorage and loaded until either
-// 		the version changes or the feature list...
+// XXX revise: cache group naming...
+// 		currently the used groups are:
+// 			Session groups -- cleared on .clear() ('cache')
+// 				session-*
+// 				view-*
+// 			View groups -- cleared by crop/collection ('crop', 'collections')
+// 				view-*
+// 			Changes groups -- cleared when specific changes are made ('changes')
+// 				*-data
+// 				*-images
+// 				...
+// 		This approach seems not flexible enough...
+// 		Ideas:
+// 			- use keywords in group names??
+// XXX should we consider persistent caches -- localStorage???
 var CacheActions = actions.Actions({
 	config: {
 		// Enable/disable caching...
@@ -1062,11 +1074,30 @@ var CacheActions = actions.Actions({
 		// 		action is available...
 		'pre-cache-progress': 3000,
 
+
+		// Groups to be cleared at the longest on session change...
+		//
+		// These include by default:
+		// 	'session'			- will live through the whole session.
+		// 	'view'				- cleared when view changes
+		//
+		'cache-session-groups': [
+			'session',
+			'view',
+		],
+
 		// XXX handler cache..
 	},
 
 	// Cache utility method...
 	//
+	// 	.cache(title, handler)
+	// 		-> value
+	//
+	// 	.cache(group, title, handler)
+	// 		-> value
+	//
+	//
 	// Example use:
 	// 	someAction: [
 	// 		function(){
@@ -1086,18 +1117,106 @@ var CacheActions = actions.Actions({
 	// 					return data
 	// 				}) }],
 	//
-	cache: function(title, lister){
+	// XXX what should the default group be???
+	// XXX should this be an action???
+	__cache: null,
+	cache: function(title, handler){
+		var group = 'global'
+		// caching disabled...
 		if(!(this.config || {}).cache){
-			return lister.call(this)
-		}
+			return handler.call(this) }
+		arguments.length > 2
+			&& ([group, title, handler] = arguments)
 		var cache = this.__cache = this.__cache || {}
+		cache = cache[group] = cache[group] || {}
 		return (cache[title] = 
 			title in cache ? 
-				// pass the cached data for cloning/update to the lister...
-				lister.call(this, cache[title])
-				: lister.call(this))
-	},
+				// pass the cached data for cloning/update to the handler...
+				handler.call(this, cache[title])
+				: handler.call(this)) },
+	clearCache: ['System/Clear cache',
+		doc`
 
+			Clear cache fully...
+			.clearCache()
+			
+			Clear title (global group)...
+			.clearCache(title)
+
+			Clear title from group...
+			.clearCache(group, title)
+
+			Clear out the full group...
+			.clearCache(group, '*')
+
+
+		NOTE: a group can be a string, list or a regexp object.
+		`,
+		function(title){
+			var that = this
+			// full clear...
+			if(arguments.length == 0 
+					|| (arguments[0] == '*' 
+						&& arguments[1] == '*')){
+				delete this.__cache
+			// partial clear...
+			} else {
+				var group = 'global'
+				// both group and title given...
+				arguments.length > 1
+					&& ([group, title] = arguments)
+
+				// regexp...
+				// NOTE: these are only supported in groups...
+				if(group != '*' && group.includes('*')){
+					group = new RegExp('^'+ group +'$', 'i')
+					group = Object.keys(this.__cache || {})
+						.filter(function(g){
+							return group.test(g) }) }
+
+				// clear title from each group...
+				if(group == '*' || group instanceof Array || group instanceof RegExp){
+					;(group instanceof Array ?
+						group
+					: group instanceof RegExp ? 
+						Object.keys(this.__cache || {})
+							.filter(function(g){
+								return group.test(g) })
+					: Object.keys(this.__cache || {}))
+						.forEach(function(group){
+							that.clearCache(group, title) })
+				// clear multiple titles...
+				} else if(title instanceof Array){
+					title.forEach(function(title){
+						delete ((that.__cache || {})[group] || {})[title] })
+				// clear group...
+				} else if(title == '*'){
+					delete (this.__cache || {})[group]
+				// clear title from group...
+				} else {
+					delete ((this.__cache || {})[group] || {})[title] } } }],
+
+	// special caches...
+	//
+	sessionCache: ['- System/',
+		doc`Add to session cache...
+
+			.sessionCache(title, handler)
+				-> value
+
+
+		This is a shorthand to:
+
+			.cache('session', title, handler)
+				-> value
+
+
+		NOTE: also see .cache(..)
+		`,
+		'cache: "session" ...'],
+
+
+	// XXX doc: what are we precaching???
 	preCache: ['System/Run pre-cache',
 		doc`Run pre-cache...
 
@@ -1120,8 +1239,7 @@ var CacheActions = actions.Actions({
 				var done = 0
 				var attrs = []
 				for(var k in this){
-					attrs.push(k)
-				}
+					attrs.push(k) }
 				var l = attrs.length
 
 				var started = Date.now()
@@ -1131,45 +1249,25 @@ var CacheActions = actions.Actions({
 					var a = Date.now()
 					var b = a
 					if(attrs.length == 0){
-						return
-					}
-
+						return }
 					while(b - a < c){
 						this[attrs.pop()]
 						b = Date.now()
 						done += 1
-
 						this.showProgress
 							&& (show === true || (show && b - started > show))
-							&& this.showProgress('Caching', done, l)
-					}
-
+							&& this.showProgress('Caching', done, l) }
 					t === true ?
 						tick()
-						: setTimeout(tick, t)
-				}.bind(this)
+						: setTimeout(tick, t) }.bind(this)
 
-				tick()
-			}
-		}],
-	clearCache: ['System/Clear cache',
-		function(title){
-			if(title){
-				delete (this.__cache|| {})[title]
-
-			} else {
-				delete this.__cache
-			}
-		}],
-
-	// XXX do we need this...
+				tick() } }],
 	reCache: ['System/Re-cache',
 		function(t){
 			this
 				.clearCache()
 				.preCache(t) }],
 
-
 	toggleHandlerCache: ['System/Action handler cache',
 		makeConfigToggler('action-handler-cache', 
 			['off', 'on']/*,
@@ -1192,15 +1290,16 @@ module.Cache = ImageGridFeatures.Feature({
 	actions: CacheActions,
 
 	handlers: [
+		// System...
 		['start.pre', 
 			function(){ 
+				this.clearCache()
 				var t = this.config['pre-cache']
 				t === true ?
 					this.preCache('now') 
 				: t >= 0 ?
 					this.preCache() 
-				: false
-			}],
+				: false }],
 		['start',
 			function(){
 				// XXX this breaks loading...
@@ -1208,7 +1307,6 @@ module.Cache = ImageGridFeatures.Feature({
 				// 		there seems to be no problems...
 				//this.toggleHandlerCache(this.config['action-handler-cache'] || 'on')
 			}],
-
 		/*/ XXX clear cache when feature/action topology changes...
 		[[
 			'inlineMixin',
@@ -1222,6 +1320,16 @@ module.Cache = ImageGridFeatures.Feature({
 				this.clearCache()
 			}],
 		//*/
+
+
+		// clear session cache...
+		['clear',
+			//'clearCache: "(session|view)(-.*)?" "*" -- Clear session cache'],
+			function(){
+				this.clearCache(`(${ 
+					(this.config['cache-session-groups'] 
+							|| ['session', 'view'])
+						.join('|') })(-.*)?`) }],
 	],
 })
 
@@ -2148,6 +2256,16 @@ module.Changes = ImageGridFeatures.Feature({
 					this.changes = JSON.parse(JSON.stringify(data.changes))
 				}
 			}],
+
+		// clear caches relating to stuff we just changed...
+		['markChanged',
+			function(_, section){
+				section = (section instanceof Array ?
+						section
+						: [section])
+					.map(function(section){ 
+						return '.*-'+section })
+				this.clearCache(section, '*') }],
 	],
 })
 
diff --git a/Viewer/features/ui-status.js b/Viewer/features/ui-status.js
index 0b3e1fd1..de6a752c 100755
--- a/Viewer/features/ui-status.js
+++ b/Viewer/features/ui-status.js
@@ -25,8 +25,7 @@ var base = require('features/base')
 
 var makeStateIndicator = function(type){
 	return $('<div>')
-		.addClass('state-indicator-container ' + type || '')
-}
+		.addClass('state-indicator-container ' + type || '') }
 
 // XXX do we need this???
 var makeStateIndicatorItem = function(container, type, text){
@@ -35,8 +34,7 @@ var makeStateIndicatorItem = function(container, type, text){
 			.attr('text', text)
 	this.dom.find('.state-indicator-container.'+container)
 		.append(item)
-	return item
-}
+	return item }
 
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -102,6 +100,13 @@ var StatusBarActions = actions.Actions({
 		},
 	},
 
+
+	get __statusbar_cache(){
+		return this.cache('view-data', 'statusbar', 
+			function(data){ 
+				return data || {}}) },
+
+
 	__statusbar_elements__: {
 		/* item template...
 		item: function(item){
@@ -133,8 +138,7 @@ var StatusBarActions = actions.Actions({
 		index: function(item, gid, img){
 			// cleanup...
 			if(item == null){
-				return 
-			}
+				return }
 
 			var that = this
 			gid = gid || this.current
@@ -162,8 +166,7 @@ var StatusBarActions = actions.Actions({
 							// toggle index state...
 							.click(function(){
 								that.toggleStatusBarIndexMode()
-								that.updateStatusBar()
-							})
+								that.updateStatusBar() })
 						// editable...
 						: $('<span>')
 							.addClass('position editable')
@@ -182,40 +185,35 @@ var StatusBarActions = actions.Actions({
 								//event.stopPropagation()
 
 								(that.config['status-bar-index'] || {})['live-update-on-edit']
-									&& go(parseInt($(this).text()))
-							})
+									&& go(parseInt($(this).text())) })
 							.focus(function(){
-								$(this).selectText()
-							})
+								$(this).selectText() })
 							.blur(function(){
-								that.updateStatusBar()
-							}))
+								that.updateStatusBar() }))
 					.append($('<span>')
 						.addClass('length')
 						.attr('info', 'Image count (click to toggle ribbon/global)')
 						// toggle index state...
 						.click(function(){
 							that.toggleStatusBarIndexMode()
-							that.updateStatusBar()
-						}))
+							that.updateStatusBar() }))
 
 			} else {
-				var type = item.attr('type')
-			}
+				var type = item.attr('type') }
 
 			// NOTE: using .toggleStatusBarIndexMode(..) here will fall
 			// 		into an infinite recursion...
 			var cls = (that.config['status-bar-index'] || {})['mode'] || 'normal'
 
-			// XXX get the cached length...
-			// XXX make this part of the status bar cache...
-			var cache = this.__statusbar_index_length_cache || []
-			cache = cache[0] == cls ?
-				cache[1]
+			// get the cached length...
+			var cache = this.__statusbar_cache.index_total
+			cache = cache ? 
+				(cache[0] == cls 
+					&& cache[1])
 				: null
 
 			// empty view...
-			if(this.data){
+			if(!this.data){
 				var i = -1
 				var l = 0
 
@@ -234,11 +232,16 @@ var StatusBarActions = actions.Actions({
 			// ribbon index...
 			} else {
 				var i = this.data.getImageOrder('ribbon', gid)
-				var l = cache = 
-					cache || this.data.getImages(gid).len }
+				var r = this.current_ribbon
+				var l = cache 
+					&& cache instanceof Array 
+					&& cache[0] == r
+					&& cache[1]
+				l = l || this.data.getImages(gid).len
+				cache = [r, l] }
 
-			// XXX save cache...
-			this.__statusbar_index_length_cache = [cls, cache]
+			// save cache...
+			this.__statusbar_cache.index_total = [cls, cache]
 
 			// update...
 			item
@@ -250,13 +253,11 @@ var StatusBarActions = actions.Actions({
 				.find('.length')
 					.text(l > 0 ? ('/' + l) : '')
 
-			return item
-		},
+			return item },
 		ribbon: function(item, gid, img){
 			// cleanup...
 			if(item == null){
-				return 
-			}
+				return }
 
 			var that = this
 
@@ -294,8 +295,7 @@ var StatusBarActions = actions.Actions({
 						}))
 					.append($('<span>')
 						.addClass('ribbon-count')
-						.attr('info', 'Ribbon count'))
-			}
+						.attr('info', 'Ribbon count')) }
 
 			item
 				.find('.ribbon-number')
@@ -312,22 +312,18 @@ var StatusBarActions = actions.Actions({
 				item[0].setAttribute('base', '')
 
 			} else {
-				item[0].removeAttribute('base')
-			}
+				item[0].removeAttribute('base') }
 
-			return item
-		},
+			return item },
 		changes: function(item, gid, img){
 			// cleanup...
 			if(item == null){
-				return 
-			}
+				return }
 
 			if(typeof(item) == typeof('str')){
 				item = $('<span>')
 					.addClass('changes')
-					.attr('info', 'Unsaved changes')
-			}
+					.attr('info', 'Unsaved changes') }
 
 			//item.html(this.changes !== false ? 
 			//	this.config['status-bar-changes-text'] || '*' 
@@ -337,14 +333,12 @@ var StatusBarActions = actions.Actions({
 				this.config['status-bar-changes-text'] || '*' 
 				: '')
 
-			return item
-		},
+			return item },
 		// XXX handle path correctly...
 		gid: function(item, gid, img){
 			// cleanup...
 			if(item == null){
-				return 
-			}
+				return }
 
 			var that = this
 			gid = gid || this.current
@@ -363,12 +357,10 @@ var StatusBarActions = actions.Actions({
 						// select the text...
 						// XXX should this also copy???
 						.click(function(){
-							$(this).selectText()
-						}))
+							$(this).selectText() }))
 
 			} else {
-				var type = item.attr('type')
-			}
+				var type = item.attr('type') }
 
 			// update...
 			var txt = ''
@@ -386,14 +378,14 @@ var StatusBarActions = actions.Actions({
 				text = (img && img.path && ((img.base_path || '') +'/'+ img.path) || '---')
 					// remove /./
 					.replace(/[\\\/]\.[\\\/]/, '/')
-				txt = img && ((img.name || '') + (img.ext || '')) || text.split(/[\\\/]/).pop()
-			}
+				txt = img 
+					&& ((img.name || '') + (img.ext || '')) 
+					|| text.split(/[\\\/]/).pop() }
 
 			item.find('.shown').text(txt)
 			item.find('.hidden').text(text)
 
-			return item
-		},
+			return item },
 		path: 'gid',
 		'edit-mode': function(item){
 			// cleanup...
@@ -401,21 +393,20 @@ var StatusBarActions = actions.Actions({
 				this.__edit_mode_indicator_update
 					&& this.off('keyPress', this.__edit_mode_indicator_update)
 				delete this.__edit_mode_indicator_update
-				return
-			}
+				return }
 
-			var update = this.__edit_mode_indicator_update = this.__edit_mode_indicator_update 
-				|| (function(){
-					var caps = this.keyboard.capslock
-					caps = typeof(event) != 'undefined' && event.getModifierState ? 
-						event.getModifierState('CapsLock')
-						: caps
-					item
-						.attr('info', 'Edit mode ' 
-							+ (caps ? 'on' : 'off')
-							+ ' (Click to update / Press CapsLock to toggle)')
-						[caps ? 'addClass' : 'removeClass']('on')
-				}).bind(this)
+			var update = this.__edit_mode_indicator_update = 
+				this.__edit_mode_indicator_update 
+					|| (function(){
+						var caps = this.keyboard.capslock
+						caps = typeof(event) != 'undefined' && event.getModifierState ? 
+							event.getModifierState('CapsLock')
+							: caps
+						item
+							.attr('info', 'Edit mode ' 
+								+ (caps ? 'on' : 'off')
+								+ ' (Click to update / Press CapsLock to toggle)')
+							[caps ? 'addClass' : 'removeClass']('on') }).bind(this)
 
 			// cleanup interval handling...
 			this.__edit_mode_indicator_update_interval
@@ -426,8 +417,7 @@ var StatusBarActions = actions.Actions({
 			if(item == null){
 				this.off('keyPress', update)
 				this.dom.off('focus', update)
-				return
-			}
+				return }
 
 			// setup...
 			if(typeof(item) == typeof('str')){
@@ -441,8 +431,7 @@ var StatusBarActions = actions.Actions({
 					.click(update)
 
 				this.on('keyPress', update)
-				this.dom.focus(update)
-			}
+				this.dom.focus(update) }
 
 			// update timer...
 			// NOTE: this is needed so as to reflect changes to settings...
@@ -454,15 +443,13 @@ var StatusBarActions = actions.Actions({
 			// update state...
 			update()
 
-			return item
-		},
+			return item },
 		// XXX show menu in the appropriate corner...
 		// XXX remove the type+ed class...
 		mark: function(item, gid, img){
 			// cleanup...
 			if(item == null){
-				return 
-			}
+				return }
 
 			gid = gid || this.current
 			var that = this
@@ -484,12 +471,10 @@ var StatusBarActions = actions.Actions({
 						evt.preventDefault()
 						evt.stopPropagation()
 
-						that.browseActions('/'+ type.capitalize() +'/')
-					})
+						that.browseActions('/'+ type.capitalize() +'/') })
 
 			} else {
-				var type = item.attr('type')
-			}
+				var type = item.attr('type') }
 
 			// NOTE: we are not using .toggleMark('?') and friends 
 			// 		here to avoid recursion as we might be handling 
@@ -503,8 +488,7 @@ var StatusBarActions = actions.Actions({
 					'removeClass' 
 					: 'addClass']('on')
 
-			return item
-		},
+			return item },
 		bookmark: 'mark', 
 	},
 
@@ -520,8 +504,7 @@ var StatusBarActions = actions.Actions({
 			function(){ 
 				// no viewer yet...
 				if(!this.ribbons || !this.dom){
-					return $()
-				}
+					return $() }
 
 				var bar = this.dom.find('.state-indicator-container.global-info') 
 				if(bar.length == 0){
@@ -543,17 +526,14 @@ var StatusBarActions = actions.Actions({
 						.on('mouseout', function(){
 							bar.find('.info').empty()
 						})
-						.appendTo(this.dom)
-				}
-				return bar
-			}, 
+						.appendTo(this.dom) }
+				return bar }, 
 			function(){ return Object.keys(this.config['status-bars']).concat(['none']) },
 			// XXX check if we will be getting gid reliably...
 			function(state, bar, gid){ 
 				// do not do anything unless the status bar exists...
 				if(bar.length == 0){
-					return
-				}
+					return }
 				var that = this
 				this.config['status-bar'] = state 
 
@@ -564,8 +544,7 @@ var StatusBarActions = actions.Actions({
 					var handler = elems[key] || base_elems[key]
 
 					if(handler == null){
-						return
-					}
+						return }
 
 					// handle aliases...
 					var seen = []
@@ -576,15 +555,13 @@ var StatusBarActions = actions.Actions({
 						if(seen.indexOf(handler) >= 0){
 							console.error('state indicator alias loop detected at:', key)
 							handler = null
-							break
-						}
-					}
+							break } }
 
-					return handler
-				}
+					return handler }
 
 				// clear...
 				if(state == 'none' || !bar.hasClass(state)){
+					this.clearStatusBarCache()
 					// notify items that they are removed...
 					bar.children()
 						.each(function(i, item){
@@ -592,25 +569,21 @@ var StatusBarActions = actions.Actions({
 							var type = item.attr('type') 
 
 							if(type == null){
-								return
-							}
+								return }
 
 							var handler = _getHandler(type)
 
 							if(handler != null){
-								handler.call(that, null) 
-							}
+								handler.call(that, null) }
 						})
-					bar.empty()
-				}
+					bar.empty() }
 
 				if(state == 'none'){
 					!('none' in this.config['status-bars'])
 						// XXX this feels like a hack...
 						&& setTimeout(function(){ this.toggleStatusBar(0) }.bind(this), 0)
 					//return Object.keys(this.config['status-bars'])[0]
-					return
-				}
+					return }
 
 				// build/update...
 				gid = gid || this.current
@@ -642,11 +615,9 @@ var StatusBarActions = actions.Actions({
 							item = (handler ? 
 									handler.call(that, item, gid, img) 
 									: $('<span>'))
-								.attr('type', item)
-						}
+								.attr('type', item) }
 
-						bar.append(item)
-					})
+						bar.append(item) })
 
 				// update...
 				} else {
@@ -656,17 +627,12 @@ var StatusBarActions = actions.Actions({
 							var type = item.attr('type') 
 
 							if(type == null){
-								return
-							}
+								return }
 
 							var handler = _getHandler(type)
 
 							if(handler != null){
-								handler.call(that, item, gid, img) 
-							}
-						})
-				}
-			},
+								handler.call(that, item, gid, img) } }) } },
 			null)],	
 	updateStatusBar: ['- Interface/Update satus bar',
 		'toggleStatusBar: "!"'],
@@ -675,8 +641,10 @@ var StatusBarActions = actions.Actions({
 		function(){
 			var mode = this.toggleStatusBar('?')
 			this.toggleStatusBar('none')
-			this.toggleStatusBar(mode)
-		}],
+			this.toggleStatusBar(mode) }],
+	clearStatusBarCache: ['- Interface/Clear status bar cache',
+		'clearCache: "*" "statusbar"'],
+
 
 	// XXX should this blink the on state only???
 	statusItemBlink: ['- Interface/',
@@ -685,8 +653,7 @@ var StatusBarActions = actions.Actions({
 		NOTE: type is the same as in .__statusbar_elements__`,
 		function(type){
 			if(type == null){
-				return
-			}
+				return }
 
 			var gid = this.current
 			var item = this.dom.find(`.state-indicator-container.global-info [type=${type}]`) 
@@ -695,42 +662,36 @@ var StatusBarActions = actions.Actions({
 			item
 				.removeClass('blink')
 				.addClass('blink')
-				.on('animationend', function(){ item.removeClass('blink') })
-		}],
+				.on('animationend', function(){ item.removeClass('blink') }) }],
 
 	// XXX should these be here???
 	// XXX should this show a dialog???
 	editStatusBarIndex: ['- Interface/Edit image focus position in statusbar',
 		function(){
 			if((this.config['status-bar-index'] || {} )['editable']){
-				this.toggleStatusBar('?') == 'none' && this.toggleStatusBar()
-
+				this.toggleStatusBar('?') == 'none' 
+					&& this.toggleStatusBar()
 				// XXX do this better...
-				this.dom.find('.global-info .index .position').focus().click()
-			}
-		}],
+				this.dom.find('.global-info .index .position').focus().click() } }],
 	editStatusBarRibbon: ['- Interface/Edit ribbon focus position in statusbar',
 		function(){
-			this.toggleStatusBar('?') == 'none' && this.toggleStatusBar()
-
+			this.toggleStatusBar('?') == 'none' 
+				&& this.toggleStatusBar()
 			// XXX do this better...
-			this.dom.find('.global-info .ribbon-number').focus().click()
-		}],
+			this.dom.find('.global-info .ribbon-number').focus().click() }],
 	toggleStatusBarIndexMode: ['Interface/Status bar index mode',
 		toggler.CSSClassToggler(
 			function(){ 
 				return this.dom.find('.global-info .index') },
 			['normal', 'loaded', 'global'],
 			function(state){
-				this.toggleStatusBar('?') == 'none' && this.toggleStatusBar()
-
+				this.toggleStatusBar('?') == 'none' 
+					&& this.toggleStatusBar()
 				// prepare for saving the config...
 				this.config['status-bar-index'] = 
 					JSON.parse(JSON.stringify(this.config['status-bar-index']))
 				this.config['status-bar-index']['mode'] = state
-
-				this.updateStatusBar()
-			})],
+				this.updateStatusBar() })],
 
 	// XXX revise...
 	showStatusBarInfo: ['- Interface/',
@@ -807,12 +768,10 @@ module.StatusBar = core.ImageGridFeatures.Feature({
 	handlers: [
 		['start',
 			function(){
-				this.toggleStatusBar(this.config['status-bar'])
-			}],
+				this.toggleStatusBar(this.config['status-bar']) }],
 		['focusImage clear markChanged refresh',
 			function(){
-				this.updateStatusBar()
-			}],
+				this.updateStatusBar() }],
 		[[
 			'tag',
 			'untag',
@@ -823,14 +782,12 @@ module.StatusBar = core.ImageGridFeatures.Feature({
 						&& (gids.indexOf('current') >= 0 
 							|| gids.indexOf(this.current) >= 0)
 						|| this.data.getImage(gids) == this.current){
-					this.updateStatusBar()
-				}
-			}],
+					this.updateStatusBar() } }],
 
 		['ribbonPanning.post',
 			function(_, gid){
-				gid == this.data.getRibbon() && this.updateStatusBar()
-			}],
+				gid == this.data.getRibbon() 
+					&& this.updateStatusBar() }],
 
 		// blink status mark indicators on toggle...
 		['toggleMark',
@@ -853,13 +810,11 @@ module.StatusBar = core.ImageGridFeatures.Feature({
 		],
 			function(workspace){
 				if(!workspace || workspace in this.workspaces){
-					return
-				}
+					return }
 
 				this.config['status-bar'] = 
 					(this.config['status-bar-workspace-defaults'][workspace] 
-						|| this.config['status-bar'])
-			}],
+						|| this.config['status-bar']) }],
 		['loadWorkspace',
 			core.makeWorkspaceConfigLoader(
 				function(){ 
@@ -871,9 +826,7 @@ module.StatusBar = core.ImageGridFeatures.Feature({
 					} else {
 						'status-bar' in workspace ?
 							this.toggleStatusBar(workspace['status-bar'])
-							: this.toggleStatusBar(this.config['status-bar'])
-					}
-				})],
+							: this.toggleStatusBar(this.config['status-bar']) } })],
 	],
 })
 
diff --git a/Viewer/imagegrid/data.js b/Viewer/imagegrid/data.js
index 98889a36..c8ec6333 100755
--- a/Viewer/imagegrid/data.js
+++ b/Viewer/imagegrid/data.js
@@ -13,6 +13,7 @@
 
 var sha1 = require('ext-lib/sha1')
 
+var types = require('lib/types')
 var object = require('lib/object')
 
 var tags = require('imagegrid/tags')
@@ -223,6 +224,7 @@ var DataPrototype = {
 	ribbon_order: null,
 	ribbons: null,
 
+	//__current: null,
 	get current(){
 		return this.__current = this.__current 
 			|| this.getImages(this.ribbon_order[0])[0]
@@ -230,6 +232,7 @@ var DataPrototype = {
 	set current(value){
 		this.focusImage(value) },
 
+	//__base: null,
 	get base(){
 		return this.__base || this.ribbon_order[0] },
 	set base(value){
@@ -237,13 +240,18 @@ var DataPrototype = {
 			this.getRibbon(value)
 			: value },
 
+	// NOTE: experiments with wrapping data in Proxy yielded a 
+	// 		significant slowdown on edits...
+	//__order: null,
 	get order(){
 		return this.__order },
 	set order(value){
 		delete this.__order_index
 		this.__order = value },
+	//__order_index: null,
 	get order_index(){
-		return this.__order_index = this.__order_index || this.order.toKeys() },
+		return this.__order_index = 
+			this.__order_index || this.order.toKeys() },
 
 
 
@@ -1027,16 +1035,16 @@ var DataPrototype = {
 	// 		order.
 	getImageOrder: function(context, target, mode, list){
 		if(context == 'loaded' || context == 'global'){
-			return this.getImages('loaded').indexOf(this.getImage(target, mode, list))
+			return this.getImages('loaded').lastIndexOf(this.getImage(target, mode, list))
 
 		} else if(context == 'ribbon'){
 			var gid = this.getImage(target, mode, list)
-			return this.getImages(gid).indexOf(gid)
+			return this.getImages(gid).lastIndexOf(gid)
 
 		} else if(context == 'all'){
-			return this.order.indexOf(this.getImage(target, mode, list)) } 
+			return this.order.lastIndexOf(this.getImage(target, mode, list)) } 
 
-		return this.order.indexOf(this.getImage(context, target, mode)) },	
+		return this.order.lastIndexOf(this.getImage(context, target, mode)) },	
 
 	// Get a list of image gids...
 	//
@@ -1183,7 +1191,6 @@ var DataPrototype = {
 
 		target = this.getImage(target) 
 			|| this.getImage(target, 'after')
-		var i = list.indexOf(target)
 
 		// prepare to slice the list...
 		if(mode == 'around' || mode == 'total'){
@@ -1204,6 +1211,10 @@ var DataPrototype = {
 
 		var res = [target]
 
+		// XXX can we avoid .indexOf(..) here???
+		//var i = list.indexOf(target)
+		//var i = list.index(target)
+		var i = list.lastIndexOf(target)
 		// pre...
 		for(var n = i-1; n >= 0 && pre > 0; n--){
 			// NOTE: list may be sparse so we skip the items that are not
@@ -1227,7 +1238,9 @@ var DataPrototype = {
 		// 		in the post section...
 		if(mode == 'total' && post > 0){
 			var pad = count - res.length
-			var i = list.indexOf(res[0])
+			//var i = list.indexOf(res[0])
+			//var i = list.index(res[0])
+			var i = list.lastIndexOf(res[0])
 
 			res.reverse()
 			for(var n = i-1; n >= 0 && pad > 0; n--){
diff --git a/Viewer/package-lock.json b/Viewer/package-lock.json
index 16d9be8d..ae6cdfb3 100755
--- a/Viewer/package-lock.json
+++ b/Viewer/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "ImageGrid.Viewer.g4",
-  "version": "4.0.0a",
+  "version": "4.0.0-a",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -1110,9 +1110,9 @@
       "integrity": "sha512-9kZM80Js9/eTwXN9VXwLDC1wDJ7gIAdYU9GIzb5KJmNcLAMaW+zhgFrwFFMrcSfggUuadgnqSrS41E4XLe8JZw=="
     },
     "ig-types": {
-      "version": "5.0.18",
-      "resolved": "https://registry.npmjs.org/ig-types/-/ig-types-5.0.18.tgz",
-      "integrity": "sha512-8c16slG/J0qC9oYW1Mx6oSriEYKEY/HLs4SvgWDLqac/qx/nMaa6HlEUA/fi+whGxvTk03t4s/IKca+MKWV9oQ==",
+      "version": "5.0.20",
+      "resolved": "https://registry.npmjs.org/ig-types/-/ig-types-5.0.20.tgz",
+      "integrity": "sha512-d2IEwY3ZDSWxn2PY0e7XxMzuOPWzeK/py0sBgqfoCNbKlc4IHEogFwoQIv0C4EZdcXL0cJOsCo74NwbetoSWiA==",
       "requires": {
         "ig-object": "^5.4.12",
         "object-run": "^1.0.1"
diff --git a/Viewer/package.json b/Viewer/package.json
index a6ab2f98..4ea92719 100755
--- a/Viewer/package.json
+++ b/Viewer/package.json
@@ -32,7 +32,7 @@
     "ig-argv": "^2.15.0",
     "ig-features": "^3.4.2",
     "ig-object": "^5.4.12",
-    "ig-types": "^5.0.18",
+    "ig-types": "^5.0.20",
     "moment": "^2.29.1",
     "object-run": "^1.0.1",
     "requirejs": "^2.3.6",