I want to disable the integrated webcam on my iMac G5, in favor of another more flexible and powerful (i.e. QuickCam from Logitech). I'm not happy with the webcam at the top of my monitor (it's useless when the light is not good), and I can't seem to make the other one work with software as Delicious Library, Yahoo Messenger or even iChat. Could someone please advise on the matter? Thanks in advance.