I'm trying to record gameplay of Halo CE universal binary using iShow U HD. I have noticed that all the videos I have recorded so far are quite jittery. The game settings allow me to turn vsync on which I have done so I don't think its a frame rate issue. In any case, the game is not jittery whilst playing it. It is only the output, the video that is. Is this because the mac is having to run the video game software at the same time it is running iShow U to record the screen? Is it simply a matter of too much going on for my 2 x 2.66 GHz Dual Core processors? If not, what can I do to ensure smooth video playback? Any suggestions would be welcome.