Try this /etc/X11/xorg.conf Section "Device" Identifier "Configured Video Device" Driver "radeon" Option "AccelMethod" "XAA" EndSection
Copy this there and then reboot.
Try this /etc/X11/xorg.conf Section "Device" Identifier "Configured Video Device" Driver "radeon" Option "AccelMethod" "XAA" EndSection
Copy this there and then reboot.