Ok... I updated compitz, downloaded the newest ati-driver and installet that again. First off I still have the problem that the 3D-Desktop hangs after a little while, usually after five minutes. And on top of that gl games tend to skip or lose their acceleration when started on the 3D desktop and what surprises me most is that simple games like toppler or CDvST run sluggish while they used to work great in standard VESA mode, which gives me the impression that either the latest ATI driver or the compitz update turned out even more buggy than the older ones
Also I cannot select AIGLX on the 3D desktop setup. It gives me the option but it's greyed out and I can't select to use that instead of XGL. What's up with that now??