I have a 2.0Ghz Core Duo Macbook with 2GB installed RAM. It normally works great, but whenever I try to record anything in Garageband (newest version) with my MIDI keyboard the fan comes on and spins at top speed as long as I'm recording. When it does this it slows the computer down a bit and it even caused Garageband to crash at one point when I was trying to rewind to the beginning of the recorded track. The fan will come on sometimes when I'm working with a large file in Photoshop, but not to this degree. Could this have something to do with the shared memory? I would have thought 2GB would be enough. Anyone have any idea what might be causing this?