cannot restore ipod
Ny son forgot his passcode so we are trying to restore the iPod by putting it into recovery mode. When it asks for the apple id for the iPod, I put in the correct apply ID and it says "**** cannot be used to unlock this iPod" (**** being our apple ID). If I try a different password it tells me that the apple ID or password is incorrect, so I know I have used the right password for the apple ID but it is not letting me unlock the iPod. What can I do?