I'll try and keep this brief...

I went to sync my iPhone5 with my new iMac. I am now stuck in this loop:
the iPhone backs up and syncs contacts, mail, etc. then when it gets to the music, I get this message:

"This computer is no longer authorized to play purchased items that are on the iPhone "Bill's iPhone". Would you like to authorize this computer for items purchased from the iTunes store? if you do not authorize this computer, XX items, inlcuding. "xxxx" will be removed from the iPhone."

I hit the authorize button and the account dialogue box opens. Interestingly, it defaults to a .aol account that I haven't used in YEARS. So i change it to my current iTunes account info and enter the correct password. I then get this dialogue:

"This computer is already authorized. including this one, you have authorized 3 computers out of your available 5."

I hit ok...and then I am faced with the exact same dialogue box starting with "this computer is no longer authorized to play purchased items that are on the iPhone "Bill's iPhone". And the whole thing goes again…

I tried deauthorizing iTunes and downloading a fresh copy....no joy there.

Any help or suggestions are much appreciated!

Bill