Window redraw problems caused by OnDemandVBlankInterrupts
I'm using X.Org X Server 1.6.3 with the 190.36 driver. I have experienced redraw problems with compiz where parts of windows were not correctly updated and sometimes even remained completely black. I have seen similar problems with the 185.18.36 driver. The problems did NOT go away even when I enabled "Force synchronization between X and GLX" in the compiz workaround plugin.
However, the problem did go away immediately after I disabled OnDemandVBlankInterrupts in my Xorg.conf. Therefore, I believe the redraw problem is related to that option.
This is a heads up to the NVIDIA developers so they can start digging in that area. The chip is a Quadro NVS 140M.