[SOLVED] Penumbra Overture demo works, full game doesn't

[Crustadelic]

I have a problem! And I haven't found a similar one that has been solved.
So Penumbra Overture demo worked perfectly but when I got the full game, after the introduction when the game starts everything goes Black! Though I can still see the eye and the hand when there is an object in front of me.
I have even turned the resolution to 640 x 480 and the shader quality to the lowest. By doing that sometimes it isn't black but I can't see some objects or they flicker so I can't really play it.

My laptop is Dell Inspiron 1545, Ubuntu 10.04 and the graphic card should work cause the demo worked but just incase it's INTEL INTEGRATED GMA 4500MHD. I'm a new Linux user so that also complicates things.

I reeeeaaaly want to play this game!