If you look at FaderMonkey's post in the
Mozilla FireFox thread, he points out that there's a weird scrollbar display, as follows:
I get this as well when using Firefox on OS X. I don't see this with any other vBulletin board, and I don't see it with Firefox on WinXP, and I don't see it with Safari on OS X.
I doubt there's an easy fix, but I thought I'd mention it here in case there is.