Vid Card Help

Hey all, I Have a problem. I'm currently running a Verto GForce 2 MX 200 AGP Card. I went to the store today and plunked down the ole' plastic and bought a Verto GForce 4 MX 420 PCI card. I installed it, loaded the latest drivers, started FS 2002 and Pow!! Absolutly abisimal Frame rates. How about 1 fps at O'hare with Mikes new 757. I lost my reflections too. I went back into BIOS and set it for PCI instead of AGP (oops) and still 1 FPS. I got 7-8 there with my MX 200 with the HJG DC-8 73 with the same settings on the sliders. Is there anything I might have missed before I go and stick this GForce 4 card up the store managers backside????System Specs: Athlon 1.7+ with 256 DDRThanks,Brian