sudo apt-get install menu menu-xdg update-menus seems to have fixed it for me.
with the interesting side effect of giving me a debian menu with launchers for several programs the run in terminals as well as several that I didn't realize were installed. -- gnome-panel eats 50% cpu for half an hour and flickers https://launchpad.net/bugs/52405 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
