Comment # 3 on bug 1139817 from Stefan Dirsch

Hmm. Could be that things look better (but slow!) with

Section "Device"
  Identifier "Default Device"
  Driver "modesetting" 
  Option "AccelMethod" "none" 
EndSection

in /etc/X11/xorg.conf.d/50-device.conf. Or with

Section "Device"
  Identifier "Default Device"
  Driver "intel" 
EndSection

(not so slow) in the same file (package xf86-video-intel needs to be
installed). Please provide /var/log/Xorg.0.log. Then we would likely have
a Mesa driver problem.