We play soldat at work and I had no problems before I got my 24" wide Dell monitor. The screen goes black for second like 30 times in a 15min round, it's very annoying and impossible to play :(

I tried different settings, and just updated to 5.6 catalysts and nothing seems to help.. any ideas?

Operating system is XP, and display adapter radeon 9600. The screen is Dell Ultrasharp 2405FPW, and is connected with DVI.

Looks like you'd have to play in windowed mode.

Can you adjust the window size or is it either fullscreen or that really small window? The resolution is 1920x1200 so the game window is Really small :(

Nope, you can't change the size of the window etc.
Either fullscreen or windowed mode, both at 640*480 pixels.

Have you tried setting different refresh rates in config.exe?