Just looking for some advice as I've not had any problems like this with a Mac before so I've no idea where to start. I've got a new 24" iMac which has been running faultlessly for the last few weeks. However, over the last day its started crashing without any seeming pattern to it. The symptoms are the same. The little spinning beachball timer comes up in whatever application I'm running. Whatever song I'm playing in iTunes continues to play. I can move the mouse around, but can't click on anything. All the keys are non-responsive although the CAPS LOCK light still comes on when the key is pushed. I've run the techtool program which came with Applecare and it goes OK. At the moment its running SuperDuper without any problems as I'm making a backup image of the disk. So its strange that I can run that program for as long as it takes, but as soon as I start doing other stuff, it falls over. Just wondering where to start really as I'm from a PC background and never had a problem with any of my Macs before?