I think this is a dupe of bug 150361. UKThom, there is a new version available, could you try that:
http://archive.ubuntu.com/ubuntu/pool/main/x/xserver-xorg-video-ati/ -- ATI display update causes lines to form on screen in Firefox https://bugs.launchpad.net/bugs/150627 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs