I think you are using or you have already used an unofficial repo (quinnstorm one?). To fix the problem, you can try to remove and reinstall the problematic packages. If you confirm that the problem is caused by an unofficial repo, this bug can be rejected.
-- Package ubuntu-desktop has broken dep on xorg https://launchpad.net/bugs/66514 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
