Seems to be a bug with the open source Radeon driver. Are you able to reproduce the same thing with the proprietary fglrx driver?
** Also affects: xserver-xorg-video-ati (Ubuntu) Importance: Undecided Status: New ** Changed in: unity Status: New => Incomplete ** Changed in: unity (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-ati in Ubuntu. https://bugs.launchpad.net/bugs/801356 Title: Lines appear at the top of the desktop, and at the bottom of some windows To manage notifications about this bug go to: https://bugs.launchpad.net/unity/+bug/801356/+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