Hello Marco,
I'm using it with the proprietary Nvidia drivers because of
http://askubuntu.com/questions/232439/lubuntu-12-04-unresponsive-windows-with-certain-applications
You can find a patch here:
https://raw.github.com/AutoStatic/nvidia-rt/master/patch-3.0-rt-nvidia.patch
Iirc it applies cleanly to 3.2 too. Not sure about newer kernel versions.
Best,
Jeremy