I solved this problem, but like the "showFlexChrome" gray bar
bug, and the "please delete my desktop" bug, it took longer than it
should have to resolve.
The solution requires ALL three of the following:
1) Add the directory containing the icons to the build path.
The name is relative and will usually be short, like "icons" or
"images". This is done by going to the Project --> Properties
--> Flex Build Path --> Add Folder --> "Type the word
'icons' in the dialog box."
2) in the .xml file, remove the prefix "icons/" from the
This is because they will be moved to bin automatically by
the step 1 directive and they do not need the subdirectory.
3) uncomment the image_16x16 and other... entries under the
<icon> tag for as many icons as you have.