Thanks westy, I was starting to worry! I'm on x64 as well, maybe the bug is specific to Firefox on 64-bit? @evant, when you tried reproducing earlier but couldn't, was that on a 32 or 64-bit machine?
Originally Posted by evant
Is there any reason you're setting the blank image? It only needs to happen in IE 6/7, in other browsers it's set as a data image so it's inline.
You're right, it doesn't make sense for normal usage - it was just intended as a contrived example to get the same effect, since you were having trouble reproducing. I still see the original bug in Firefox without modifying the BLANK_IMAGE_URL at all. Even when it's using the inline data, Firefox still seems to take a split second to load the image which messes up the menu layout. I just used the manual URL to slow down the image loading enough to inspect what was going on. Given the trouble recreating the issue, I thought it might be useful to share another method to get the same behavior.