I recently migrated from my iMac (using Snow Leopard) to a Mac Mini which has Mountain Lion 10.8.3 on it. The experience has largely been good, but the iPodTouch that I've had synced to my iMac for ages fails to sync via iTunes with my Mac Mini. In iTunes after I connect the iPodTouch: This computer is no longer authorized to play purchased items that are on the iPod "apMacBkPro's iPod". Would you like to authorize this computer for items purchased from the iTunes Store? If you do not authorize this computer, 223 songs will be removed from the iPod. "Cancel" "Don't Authorize" "Authorize" I choose "Authorize" New dialog comes up: Enter Apple ID and Password. The Apple ID automatically filled in is an obsolete one that I used to use but is an email address that I have long since lost access to. I change it to my more recent Apple ID, still several years old, enter the password and click "Authorize". New dialog comes up: This computer is already authorized. Including this one, you have authorized 2 computers out of your available 5. I choose OK, and it starts over with the dialog: This computer is no longer authorized to play purchased items that are on the iPod "apMacBkPro's iPod". ???