This is the 3rd or 4th time today. Music playing through my computer form my iPod. Then it just stops. When i go to itunes it doesn't APPEAR there is a problem, until i try to press a button. Then i get the beachball. I can sometimes force quit itunes. Sometimes not. Sometimes the entire machine locks up. I cannot eject my ipod, b/c that locks up the finder. So basically i need to reboot the machine to get functionality back.