I have this bug too. This happened only after Gnome was updated. Then I had this bug: https://launchpad.net/distros/ubuntu/+source/shadow/+bug/49976 It was fixed with the following updates but the bug mentionned ("Greeter application crashing") above appeared.
** Attachment added: "log files" http://librarian.launchpad.net/3171923/log.tar.gz -- GDM: Greeter application crashing https://launchpad.net/bugs/48936 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
