Guess this can be closed. While trying to remove whatever caused this behaviour I actually put myself into a dependency hell I cannot fix myself without putting very much time into it - and I won't have that time coming week. So I decided to just reinstall the image.
-- gdm/xorg problem https://launchpad.net/bugs/92924 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs