I own a new iMac, and there seems to be a problem that I can't solve using the standard help files. The system "freezes" whenever I have more than two programs open, especially if I use the built-in camera for video-conferencing. The cursor then turns into a spinning disc, and the computer is disabled until I power down. I know that this may sometimes happen but the frequency leads me to believe that it may be a hardware and not a software problem. I do have a valid applecare warranty, but I'm not sure what to do with it. Suggestions greatly appreciated!! Thank you!!