Same thing as the other post I replied, a lot of people seem to have this problem.
That problem does not depend on the power you have on your computer, you could have this problem with a 2 ghz, 512 MB SDRAM, Geforce 3 machine. It's simply the drivers that need to be updated.
I'm sure that you can run FS2k2 with the computer you have, mine has less power than yours and it runs like a dream.
I also had the same problem since I bought FS2k2 and someone yesterday told me how to get rid of it.
All you have to do is download the latest drivers for your video card and its about 99% sure that FS2k2 will run ok. Just uninstall FS2k2, install the new drivers and reinstall FS2k2, the problem will be gone and you'll get better frame rates.
It also resolves the airplane textures problem and it'll get you rid of the multicolor squares on the planes.
Tell me if it works