According to the upstream bug report, this is confirmed to have been due to hardware degradation.
** Changed in: xserver-xorg-video-ati (Ubuntu) Status: Triaged => Invalid -- X displays various artifacts, white lines all over the screen https://bugs.launchpad.net/bugs/391439 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs