Im having the same kind of problem, it only shows after awhile then goes and comes back again (its kind of wierd).
Amd64 4200+ dual core,
Asus A8n-sli se
2gb ram
8800gtx 163.75 drivers
windows xp home sp2
ArmA 1.09 beta but was having same issue with 1.08
Also ive tried it with all kinds of settings in game and it doesnt make any difference to the problem.
Currently using
Terrain Detail: Low
Object Detail: Normal
Texture Detail: Normal
Shading Detail: High
Postprocess Effects: Low
Anisotropic Filtering: Normal
Shadow Detail: Disabled
Antialiasing: Normal
Blood: High
