For everyone that was having problems, do me another favor and do another cache clear (don't clear cookies) and try again. I think I figured out what was wrong.......maybe.
I assume you have tried reuploading all the vbulletin files? It appears that a number of other vbulletin sites have had this problem, and it tends to stem from having file version issues (not completely uploading files during an upgrade/corrupted files/wrong encoding). Not having any issues on FF 3.0.1
I just did a bit more testing. I un-did the change I made last night and was able to reproduce the problem in IE. I re-did the change, and the problem went away. Please make sure you're clearing your cache the right way, and hell, even reboot your computer if you have to. But I was definitely able to get it to work properly
For those of you who are 100% sure you're still having problems, can you please install the latest version of Windows Live Messenger and send me a PM? WLM has a feature that will let me see your computer screen and control your keyboard and mouse and I'd like to do that to make sure everything on your end is OK
Astat was still having problems, I had him clear his cache, and it worked, so I cannot stress this enough, please clear your browser's cache before trying again. If you are not 100% sure how to do this, please let me know which browser (IE, Firefox, ect), version and operating system you're using and I will get instructions for you.
OK so I think the only one I'm awaiting further confirmation from is Hellflame. You better not disappoint