Comment 3 for bug 883523

Marking Invalid because you've installed fglrx/Catalyst driver, which does not support your video card. Please use the open-source ati/radeon driver that is installed by default.

To remove fglrx/Catalyst:

sudo apt-get remove --purge fglrx fglrx_* fglrx-amdcccle* fglrx-dev*
sudo apt-get remove --purge xserver-xorg-video-ati xserver-xorg-video-radeon
sudo apt-get install xserver-xorg-video-ati xserver-xorg-video-radeon
sudo apt-get install --reinstall libgl1-mesa-glx xserver-xorg-core
sudo mv /etc/X11/xorg.conf /etc/X11/xorg.conf.backup
sudo rm -rf /etc/ati