“random pattern tiled across the whole screen” sounds very much like this: https://bugs.freedesktop.org/show_bug.cgi?id=61321
** Bug watch added: freedesktop.org Bugzilla #61321 https://bugs.freedesktop.org/show_bug.cgi?id=61321 -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-nouveau in Ubuntu. https://bugs.launchpad.net/bugs/1181902 Title: Nouveau driver glitch on Ubuntu 13.04 will cause system to freeze under certain conditions To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1181902/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp