Well, FRAPS tends to be a jerk when it comes to recording -_- In Fraps, you should have an option to pick a range of FPS or pick your own. I suggest picking your own and trying it at that. It MIGHT work, I usually play GTA IV and get 60 FPS, with Fraps I record at 40 FPS, that way if I get lower FPS that 60, my video won't lag.