Crysis 2 In-game Problem.?

When I open up the Crysis 2 PC Demo for the first time through steam everything is alright, I set resolution at 1920x1080, hardcore graphics settings but when I go into a game my fps falls to 0-1 and my game world is transparent (invisible/see-through). I tried the game at the lowest resolution 800x600, game runs at 50-60 fps but the game world is still transparent. If anybody has this problem or knows how to fix this problem or has any suggestions please reply. Thanks in advance for who ever gives me a hand.



System Specs:



CPU: AMD Phenom 9850 Black Edition 2.5GHz

Motherboard: i have no idea

Ram: 6GB DDR2

GPU: ATI Radeon HD 5850 1GB



I'm not sure if anybody else is having problems with ATI if that even is the problem which it probably isn't because nobody else is complaining about it that I know of. And yes I have up to date drivers lol.Crysis 2 In-game Problem.?
Never had this happen to me. I am using the multiplayer demo tho so if you have the leak it could be a poor torrent.
Specs:
4gb ddr3 ram
CPU: i5-650@3.8
GPU: Radeon 5750

I play at 1400x900 cos my monitor is crap as but play at gamer because i see that as best looking. I average 60-70 fps.

You could try to reinstall it
When you get it too work add me:
I'm
Shood

Does this happen with other games?

I'm not too sure. Could it be something to do with a program running. I know when i play BFBC2 if i press tab + alt everytime a new match starts theres a black screen and then i have to press alt + tab at the start of each match.