Clod and Nvidia 3d Vision (stereoscopic)

[kikww2]

Hi everyone i read like 5 post about 3d in clod but anyone answer my question and many of them are off topic, this is not about it if is good or not, is about to make it work ok.

I have a nvidia gtx 560ssc + proyector Optoma hd66.

I can run clod perfectly with this set up, but when i set 120hz in clod settings a weird dark shadown appear in the horizon, anyone can solve this??