I believe these files are installed by gnome-menus not gnome-panel. dpkg -S nameoffile shows which package installed a particular file.
** Package changed: gnome-panel (Ubuntu) => gnome-menus (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-menus in Ubuntu. https://bugs.launchpad.net/bugs/798951 Title: Applications menu fails to open due to change to /etc/xdg/menus/gnome- applications.menu To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-menus/+bug/798951/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs