For months when I clicked on Places--> Home Folder the panel would launch gqview instead of Nautilus. So annoying.
When your Gnome menus get screwed up just
cd ~/.local/share/applications ; rm *
You can do this while logged into Gnome. Don't worry; all those .desktop files will be regenerated automatically by whatever deamon monitors .local/share/applications for changes. You will have the factory defaults reset immediately. No need to logout/login again.
I must have looked at a dozen files in .gnome2, .gnome2_private, .gtkrc-1.2-gnome2, etcetera. Why does Gnome need so fucking many config dirs and files? Why can't they all be in a single tree?
In the end I gave up and searched the forums on linuxquestions.com. That's where I found the answer after about ten minutes combing through the search results.