I have a 2011 3.4ghz i7 iMac running ML and starting, as best as I can tell, at the upgrade to 11 or 11.1, my iTunes is just locking up nearly daily. The usual signal is that my kids will say the AppleTV isn't working and I'll go in the den and iTunes won't open so I'll right click and it will say not responding, so I'll force quit. It will then work fine until who knows when, and then it will crash again. It is not quite daily but probably 5 days a week it crashes. And it SEEMS to be happening when no one is even using the computer. I already downloaded 11.1 again and installed it again but this hasn't seemed to make a difference.