I forgot to mention that attempts to narrow things down only resulted in the diagnosis of two programs that always leave core dumps (there should always have been a core dump from gedit and rhythmbox) but these dumps are not similar to this one.
-- GNOME panel crash/segfault on logout https://launchpad.net/bugs/40923 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs