forum hangs up when posting with quick reply or quick edit

[yoyoyoyo]

I have noticed a problem on my vbulletin forum, as well as some others that I have visited, that occurs when trying to post using the "quick reply" or when making a quick edit. After clicking the "submit" button the progress indicator just spins around forever, and my cursor changes to an hourglass, and the post never gets submitted. If I click on the "go advanced" button, and submit the same post from that page, the post is allowed to go through and is finally posted. This doesn't happen every time I try to post/edit, but it happens often enough to be really annoying.

I am using Firefox, so I know that THIS isn't the issue (since I made the changes suggested).

Does anyone know how to debug/fix this problem? Any help or ideas would be greatly appreciated.