Thanks Weegee. Your details show that it indeed started happening around the time when bypass landed:
Working: 0.0.10+13.10.20130828.1-0ubuntu1 Non-working: 0.0.10+13.10.20130903-0ubuntu1 -- 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/1218815 Title: [radeon] Graphic glitches and screen corruption (vertical lines) on XMir surfaces only To manage notifications about this bug go to: https://bugs.launchpad.net/mir/+bug/1218815/+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