I too have the same problem. I have attached a screen-shot of what is
happening. Basically, the whatever program is on top, gets pushed behind
the preview. When moving the preview window, it leaves a trail of images
of the preview. The screen just fails to refresh, even hitting F5 at the
desktop to
*** This bug is a duplicate of bug 96991 ***
https://bugs.launchpad.net/bugs/96991
I don't think that my problem is Compiz related as I was not using
anything related to Compiz at the time of my writing. I have since
installed and use Compiz. Now I have other applications doing this same
thing