____________________Hi Andy
Hmmm, this is dodgy, you could try Reinstalling DX8, once done try playing FS2K in Full Screen Mode, this can be accessed if I remember correctly from the View Menu. Although the GeForce Card should perform fine in windowed and full screen mode
You mentioned FS2002, well your graphics card is certainly up to the job (if it performs correctly), if you are unsure about any other specs, just post your full system specs here, and we will be able to advise!
I will do some more research into your problem in the meantime, let me know about any progress you make
Cheers
Sam