this happened to me as well...Apple sent me the following instructions which worked beautifully:
1) Sign out of the iTunes Store by choosing Sign Out from the Store menu in iTunes.
2) Visit Apple's My Info website:
http://myinfo.apple.com
3) Choose your country and preferred language. Then enter your iTunes Store account name and password and click Continue.
4) Choose Address Book from the menu on the left. On the Edit Address Book page, look at your shipping addresses at the bottom. If you have multiple shipping addresses, remove any out-of-date or duplicate addresses by clicking Delete. Also, make sure the state or province field is filled out correctly for each address. To edit an address, click Edit.
5) Now choose Phone Numbers from the menu on the left to look at your phone numbers. The area codes should be in the area code fields and the phone numbers should be in the phone number fields. If an area code is missing, or if it is in a phone number field, your account information may not save properly.
6) Make any other necessary corrections, then click the Save Changes button.
7) Click Log out in the upper-right corner.
