[BomberBoy]

Installing the (beta) drivers from nVidia fixed a similar problem for me. My FPS are somewhat lower than yours, but they are essentially the same as what they were in WinXP. I'm running Win7 RC 64 bit just fine and my PC hardware is nowhere near as good:

AMD Athlon64 3500+ (yes, a single core CPU!
2 Gig PC3200 DDR
ASUS A8N5X
GeForce 8600GTS 512Mb

Are you running in OpenGL or DirectX mode?