Video artifacts in Debian Wheezy

[Adriano Vilela Barbosa <adriano.vilela@gmail.com>]

Hello,

I've been having lots of problems with video artifacts on Debian
Wheezy for quite some time now. It's easier to see from a video:

http://www.youtube.com/watch?v=FEcPKWulVU0

This problem happens both on my laptop (Radeon graphics card using the
free radeon driver) and on my desktop (Nvidia graphics card using the
proprietary nvidia driver). The problem happens with both KDE and GTK
applications, mainly with pop-up type things (like menus, context
menus, kmix's volume slider, etc). I have desktop effects on with the
OpenGL compositor. The problems go away if I switch to Xrender
compositing, but then the desktop effects become way less smooth in
general.

Has anyone else had this problem as well? Any comments would be
greatly appreciated.

Thanks a lot,

Adriano