This problem appears to have resolved itself, although unfortunately I don't know what happened to resolve it. Closing.
** Changed in: xorg-server (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1003333 Title: Ubuntu snowcrashes frequently but with no obvious cause To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1003333/+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