Okay so I've read a lot of stories of Macs just shutting them self down but never had an issue myself - until now. I read that the main cause of this is the RAM. I've recently added 4GB to my existing factory 4GB and it's been running fine for a good 3 days. However today when streaming the football the iMac just shut itself down instantaneously. Does this mean I have faulty RAM? Kinda worried as clearly the Mac shutting down in such a manner cannot be good for its health.