I have never had an issue like this in any other game before.

What happens is that after a few minutes into the game, the screen goes back for a few seconds, and then comes back, and randomly goes completely black again. When it goes black, I can still hear sounds and my character still moves. Sometimes this black screen stays on longer and my monitor power light starts blinking as well, indicating that it is actually the display signal that is being cut off.

I did some experimentation, and found that this occurs in both OpenGL and D3D. Turning off all anisotropic filtering and anti-aliasing makes the screen flashes less frequent, but still occur.

My system:
AMD Athlon 1.4 GHz
256MB DDR mem
AMD-760 mobo
ATI Radeon 8500

Any help would be appreticated.

Problem fixed.

I was using DVI input with my LCD, and I suspected that maybe causing the problem. I switched to analouge connection, and all fixed.

hmm.. DVI is better than the analog one for LCD's... too bad