Comment 27 for bug 165093

I've listed it as invalid on nvidia-glx-new, since it most definitely isn't a problem with the nvidia driver. I've experienced it on both nvidia and ati systems(using both the free and proprietary ati drivers and nvidia-glx-new). Furthermore, it has also been reported on an Intel card above.

The only common link is that all of them were using composite at the time. There is also a bug on the xorg bugzilla, which seems to be the same problem, here (https://bugs.freedesktop.org/show_bug.cgi?id=10617). So, I've linked this bug to that. All we can do now is wait I guess :)