I've seen this as well lately. Today's lockup was followed by corrupted display of some fonts in FIrefox as well as in the "System problem detected" dialog.
-- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1160045 Title: GPU hangs, error messages and several instances of apport-gtk running To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1160045/+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