Alright I haven't tried that yet, but I did try reverting both SHOWTHREAD and postbit_legacy and modifyavatar and I still have the same problems. I will do what you suggested now, but if this new information gives you any clues, please let me know!
By the way, thanks so much for trying to help me!
--------------- Added [DATE]1216942028[/DATE] at [TIME]1216942028[/TIME] ---------------
Nevermind, I found the problem was in my navbar template. It's all fixed now.

Thread can be closed.