#2 - Oct. 13, 2010, 8:37 p.m.
I'd recommend a reset UI - full version.
Since as you noted addons may not be working until you get newer versions anyway. Certainly cannot hurt anything. Even with addons turned off it's entirely possible changes were made in the 3 folders involved in a reset UI that could be impacting things still.
To do a full reset UI, you will want to save your addons in another spot if you wish to preserve them, although if they are out of date - that may not be an issue right now.
Then rename/delete or move your WTF, Cache and Interface folders while WoW is shutdown.
Reboot your system. Note, if you are running Vista make sure your permissions are set so it does not undo your changes.
More detailed instructions for different operating systems, including Macs are here.
http://us.blizzard.com/support/article.xml?articleId=18761&searchQuery=reset%20UI&pageNumber=1