I sure wish you would tell me what you are doing. I'm running dual core AMD 3800's with 2 gigs of ram and an ATI X1600 with 512 megs of ram and I STILL get in the low teens to single digits... :P
I have the 3800 dual core too with 2 gig ddr2 memory and a Geforce 7600GT video card. Running in 32 bit Vista, the FPS is brilliant. I employed some of the older tweaks too plus the TreeX and cut down versions of the tree images too. Flying over the mountains in Spain and into the islands is around 40 fps. Humberside airport in the UK is about the same. Manchester airport uk is about 20 fps up to about 35 depending on where in the airport I am, this is all with 35% traffic. New York is about 15 fps, which is understandable, though Heathrow UK is slightly less.
Reider