I have used Beryl, Fusion and now run Compiz Fusion.
I have been having the following issue since I first tried Beryl but did not care much about it until today.
When I was playing a video (totem, VLC, etc..), I was getting a black screen instead of the video. The video would show up if I was moving the window around, but it would randomly become black again after a while or if I was doing anything while the video was playing.
My graphic card is an Intel, a friend reported no issue with an nVidia card :
VGA compatible controller: Intel Corporation Mobile 945GM/GMS/940GML Express Integrated Graphics Controller (rev 03)
The fix :
Open gstreamer-properties from the command line :
Go under the video tab and change the default output plugin from “autodetect” to “X Window System (no xv)”