Comment 1 for bug 1029085

Please try enabling vsync in the nvidia-settings dialog too. Once you've done that, you may not need it enabled in compiz. So disabling vsync in CCSM > General > OpenGL might help.

Please also run this command in a terminal, which will upload information about your system:
    apport-collect 1029085

The vsync and rendering methods are going to change dramatically (for the better) in Ubuntu 12.10. So this might be an issue we've already resolved in development. However that new faster code has not yet even been released in 12.10-alpha for you to test.