Wow, thanks. You really didn't have to bother for something that would have been solved in a month or two.

Eh, then nevermind. If the solution isn't easy, I'll probably buy a new PC this month or next month.

Oh, and I have the game through gog. I don't even have Steam.

I also have the same problem. I'm running the game on Windows XP 32-bit and with a Radeon X1600 graphics card. The demo didn't have this issue, instead it had a black diagonal line that separted the screen in 2. And I should mention that I have the latest drivers installed.