When I hook up the iPod Shuffle 2nd Gen to my MacBook Pro, Turn on iTunes, it says this iPod is open in another window. I've restarted the MacBook, but I still get the same message. I click the eject button to eject the iPod, and it goes into loading (thinking) mode, and can't get out of it. I've tried everything I could to reset the iPod but had no success. Please help.