Comment 5 for bug 212587

This is confirmed in Intrepid-beta on amd64, even with the nvidia drivers (as the nvidia drivers' vsync options don't always work, as reported around the net).

There's a good writeup on nvnews (http://www.nvnews.net/vbulletin/showthread.php?t=113599) about this issue on NVidia cards, and about how Compiz seems to be using "glXWaitVideoSyncSGI", which can be pre-empted (and thus, miss the proper vblank time) instead of glXSwapBuffers.

The nvnews thread also includes a patch which claims to help this issue a bit. It's a small patch, so it should be easy to test, and possibly may be useful for inclusion in the Debian patches to help resolve this issue.