Comment 3 for bug 179881

The above solution doesn't work always though... so I mostly just need to reboot the system. Killing X isn't the solution either.

Graphic card: 00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)
also using compiz cube with xrandr (1.2) and awn curves-look

So perhaps the problem lies in one of these applications/hardware