diff --git a/ui/TODO.otl b/ui/TODO.otl
index 8046d191..ed570736 100755
--- a/ui/TODO.otl
+++ b/ui/TODO.otl
@@ -97,6 +97,8 @@ Roadmap
 	[_] 59% High priority
 		[_] add indicator to ribbon up/down navigation in full screen...
 		| this might be a number or some kind of animation...
+		[_] BUG: sometimes opening a dir (open dialog) does not do anything...
+		| Uncaught TypeError: Cannot call method 'indexOf' of undefined -- data.js:576
 		[_] BUG: sometimes images.json folder is created...
 		[_] rework the marks.js/modes.js to enable multi-level cropping...
 		[_] 0% Priority tasks
diff --git a/ui/data.js b/ui/data.js
index e7cc4cad..bda3fa43 100755
--- a/ui/data.js
+++ b/ui/data.js
@@ -551,11 +551,16 @@ function getGIDBefore(gid, ribbon, search){
 // 		correct ribbon number...
 //
 // XXX do we need more checking???
+// XXX Race condition: when this is called while DATA is not yet fully 
+// 		loaded (old data), the from gid will not be present in 
+// 		DATA.ribbons...
 function getImageGIDs(from, count, ribbon, inclusive){
 	if(count == 0){
 		return []
 	}
 	// ribbon default value...
+	// XXX Race condition: if DATA is not yet loaded this can return 
+	// 		ribbon == null...
 	if(ribbon == null){
 		$(DATA.ribbons).each(function(i, e){ 
 			if(e.indexOf(from) >= 0){ 
diff --git a/ui/layout.css b/ui/layout.css
index 26ba8adc..2c31b40e 100644
--- a/ui/layout.css
+++ b/ui/layout.css
@@ -454,6 +454,9 @@ button:hover {
   right: 5px;
   border-radius: 50%;
   background: blue;
+  /* make the mark stand out if it is over an image with similar 
+	color/density */
+
   box-shadow: 0px 0px 7px 0px black;
   /*border: solid 1px white;*/