hi,
No expert but been playing since it came out , i believe the problem can be a lot of things, but i have had grafical errors before & it all comes down to the following:
1. overheating
2. need more memory
3. settings too high
4. heavyly loaded missions, big maps, too many a/c, lots of clouds /bad weather... etc
5.not enough power getting to g/card.
6. a bit off all of the above
i've excluded drivers as i assume you've had it for a while & the problem has just arisen.
First thing you must understand in my opinion- Don't believe that because you have a 9600 you can fly full settings all the time without damaging the card.
initially try reducing everything a bit so your flying on say 3/4 settings & give as more info. :wink:
Also search for Bigbossmalone post on a great tutorial he gave a while back, it will help you a lot.
Hope it helps