This happens when a user has installed xserver-xgl from the beerorkid repos or their many mirrors.
Several libraries have a different versioning system then ubuntu uses, and thus don't properly get included for the upgrade. Downgrading libgl1-mesa, libgl1-mesa-dri, xutils, and any other libraries installed by these repos resolves the problem. Something should be added to update-manager to properly downgrade libraries installed by these packages prior to the upgrade. -- [Dapper->Edgy] ubuntu-desktop has broken dep on xorg https://launchpad.net/bugs/66916 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
