Penumbra: Requiem Urgent Help! [FIXXED] :D

[Renegader]

Hello all, first time posting love your games.

I bought all the Penumbra games on Steam a while ago. I completed the first two games with no problems at all, but on requiem I am facing a lot of graphic error. At the very start of the game, I am facing huge FPS lag, the screen is flashing white/black and some times I get a glance at my desktop it is really unplayable.

Here is what i tried to do so far:
1- Re download the game from steam.
2- verify game cache.
3- Update my drivers.
4- Use older driver.
5- Drop all the graphics and screen resolution to low.

I have Windows 7 64bit ultimate,
GeForce GTX295 Driver version: 197.13,
CPU:Intel® Core™2 Quad CPU Q9650 @ 3.00GHz
Mother Board: EVGA 132-YW-E180-FTW Chipset :nvidia nForce 790i SLI SPP

Please if any one know what I can do help!!!!!!!!!!!!!!

I want to play this game. Thanks for reading