hmm if this is true.. I dont know any better than the framerate drops in ANY game when you start Fraps. Isnt that because your PC has to (re)play the game, capture it and write it to disk at the same time?
In game, when there arent too many cars around, I get around 90 fps on 1280*1024, 8*AA, 4*AF, all details on high.
When I capture with fraps, I have to turn everything off, and play back in a 640*480 window.. and even then it stutters..
So you are saying that that isnt normal?