Bought new iPad Air, but it keeps asking for my old Apple ID to complete the synch process
I've just purchased an iPad Air. I had changed my Apple ID some time ago. I've updated my old iPad 2 with the new Apple ID and deleted the old Apple ID from the iCloud function. Now that I'm trying to synch the two, the iPad Air first asks me for my iCloud Sign In and that seems to work with the new Apple ID, but then in the next screen, after the ToCs, it asks me to choose a back up. I choose today's backup. The problem comes in the next screen when it says Enter the Apple ID password for [old Apple ID] to use for store purchases. What do I do? Is there somewhere that I've missed signing off the old Apple ID? Please help. Thank you!
iPad, iOS 7.0.3, Air