I am having the problem of my iMac freeszing and becoming unresponsive. I can move my mouse curser around the screen, but nothing is responsive. Tried a force quit using the keyboard but that doesn't work either. I have to power my iMac on then off to restart. I think it may have something to do when I launch iTunes, and I am using CPU intensive applications? This problem has occured recently when i have been watching YouTube videos, then launched iTunes. Also on another occasion when using Ableton Live, then launched iTunes. When my iMac reboots after the freeze, and launch iTunes for the first time the "Checking iTunes Library" dialogue box appears and takes a while to load before iTunes launches. My iTunes Library is quite large, 55GB. Anybody got any trouble shooting advice? I know the console app shows errors but am not very sure what to look for. I'm running 10.6.4 and iTunes 9.2.1. Thanks.