Hi. I may just have an old card but when using compiz or beryl with wobbly windows the video dissapears when i move the windows and gets back when the windows are still. the same happens when rotating the cube. its like the playback stays on the same spot on the screen and continues playing until i release the cube and it gets on the right place. its like the video doesnt want to be inside the wobbly windows or on the right place when moving the cube. when watching youtube movies there is no problem though.
Radeon 9250, pentium 3, 512 mb ram. i know the cpu is old but the other compiz plugins run pretty smoothly anyway.