Does anyone else have this problem?

I installed FS9 on my 1 gig system with GEForce Ultra (64 megs) video. The trees all have black rectangles around them. There is a large black rectangle in the sky, probably where the sun would be, that causes the whole screen to go black if you pan around to look at it. The particles kicked up by the tires when taxiing on the ground are also large squares and rectangles. And the aircraft shadow flashes on and off.Any ideas?Thanks!Dewey