Whatever you set your fraps FPS to record, effects how fast your game plays. So if you make it 55, you should get decent game play. You'll have to make the movie slower in vegas or something, though. I recommend demoing then recording the demos.
Oh and make sure you make any demos you make in fraps smaller straight after you take them. And i think you cant record over 15 mins, the file gets to big and removes itself.
(to make them smaller either use windows movie maker and export it as the best qual possible then remove the original avi, or turn the avi into XviD.)