I have a new 20" iMac with 2 gig. of ram. In iTunes when you are scrolling up and down the music video page using the scroller bars and using your mouse. The computer will completely freeze up. You have to do a hard restart to get out of it. This was present in both the previous version and 7.4. You may have to do it several times but keep trying. There is a thread in apple discussions =iTunes on this. Has anyone had this problem? It seems to be iTunes related but will only do it on a new iMac.