Starnge polygons and textures

[Ace Macleod]

I don't know how to describe this. See the screnshoots:

Screen 1
Screen 2
Screen 3

All become clear after Alt+Tab, but after a few seconds it begins again

My system:
Athlon 1900+
2x256 Mb DDR
Gigabyte GeForceFX 5700 256 Mb (ForceWare 77.76, also I try those witch came on cd with game)
Epox nForce 2 Ultra
Windows XP SP2