Your IR pen may not be working correctly. I have the same type of mac and it works fine for me.
Open iMovie and view yourself with the pen. Press it a few times so you can see the tip of the LED. The camera can view IR (it appears orange/red). If the clicks produce short pulses of light, it's working fine. Otherwise, that might be your problem.
Hope that helps,
James
hi and thanks for your answer. I actually have an infrared modified webcam, the pen is working fine ( i've tested it on the built in webcam and on the IR cam). I'm thinking it might be a voltage / IR led power issue. maybe it's not strong enough or too strong.
i used an IR led from a remote and powered it up with 3 button cells which were in an led pen. I've tried with other power sources, AA and AAA batteries. i really don't understand what might be causing this. since the calibration is either impossible or on the contrary too fast, it's hard to guess if the IR led is too strong or too weak.
b