I followed Apple's instructions for changing Apple ID. The I validated the new one via email and the Apple ID website updated to display the new email address, it all look fine. Then I realize that iTunes and the App Store wouldn't let me do anything anymore. I couldn't log into the App Store. I couldn't do anything account related on iTunes, I just got an error message. I couldn't even log out! So, how do I change my Apple ID and actually have it work properly? Help!