I have a late 2007 iMac (20" 2.4Ghz, 320GB, 2GB) and up until a few months ago it has been running perfectly, But now after about one of of use it will the spinning wheel will appear and it does not go away for about 10 mins. After the 10 mins it is really sluggish and the wheel will continually come back. If I try and restart it, it just gets stuck on the white and grey page. But if I leave it for about an hour and come back it works fine, but only for an hour or so and it does the same thing. I have noticed that it is quite warm to touch and as it get's warmer that the compute starts to get slower and slower. Has anyone had the same problem? I really want to get this mac back to working order.