I get this too on my x800 pro. It's blatantly a driver problem but I have yet to solve it. The near / far clip plane issue is commonly known as "Z-fighting" - this happens when 2 objects share similar 3d space (one in front of the other, marginally). As the camera moves farther away, the accuracy of clipping planes reduces, thus confusing maya's renderer about which is in front of which. So it cant be that, as you could have 1 object in the scene (a cube for example) and you would get the same problem.

I'm kinda relieved someone else has it too, but also feel sorry for ya, cos i know it's a pain. If you find a fix, post it here! Cheers!