I've had problems using gamecam :S (down to incompetence that one tho :P )
Fraps is so easy to use tbh, and even the full version is so cheap!

Install fraps. Run fraps. choose from a very easy list of settings. open game. press button to start recording (F12 or something along those lines - you can choose) and there ya go ^^ press it again to stop recording.
soo easy