Bookmark context menuitem highlight disappears after hover

[GoogleCodeExporter]

What steps will reproduce the problem?
1. right-click on a bookmark in a folder on the Bookmarks Toolbar
2. hover a menuitem in the context menu
3. the background color highlight disappears after a moment

What is the expected output? The highlight should be persistent.

What version of the product are you using? On what operating system? Sbex 0.3.2 
on Fx4, Win7

Please provide any additional information below.
I've tried this in 4 separate instances of Firefox; works the same way in all 
of them. I've cycled through enabling/disabling StatusbarEx with the same 
result every time: disabled-> no problem, enabled-> highlight disappears 
shortly after hover (plus, moving the mouse cursor restores the highlight while 
you continue to hover the item--disappears again, of course, with next item). 
Same result with no other extensions installed (so not a conflict there). Very 
weird.

Original issue reported on code.google.com by [email protected] on 25 Apr 2011 at 6:50