I had the same problem. But the fixes you have suggested did not work for me. I have even reinstalled gnome-menus. This happened to me when i was altering the menu and moving 10gb of audio which failed because of insufficient disk space. This filled the 20gb partition. I'm a newbie so I'll need some help if you would like logs of any kind.
Thanks -- Alacarte emptied my Applications menu list. https://launchpad.net/bugs/61340 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
