Also of importance is the "keep keys at current frames" option box. If you check this and then reset your FPS your keys will remain where you put them ie: a key at frame 20 will stay at frame 20. If it is unchecked the keys will scale according to your new FPS settings so the keys will move to different frames. You may wind up with keys on half frames and quarter frames as well which is a pain, so if you choose to go this route you should pop all your keys back to the nearest whole frame.

Cheers,

Pat