Keeps saying computer not authorized, when I click "authorize", it tells me computer is already authorized!

I just plugged in an iPhone 4S (running iOS 6.1.3) into a Macbook running Snow Leopard (10.6.8) for the first time. The MacBook is a replacement for an older, now-dead MacBook; I "cloned" the old onto the new using the bult-in Apple utilities. The iPhone starts to sync, and then I get a pop-up saying "This computer is no longer authorized" to use iTunes (along with a warning that 21 apps will be deleted from the phone if I don't authorize the computer).

When I click "Authorize," I get the usual AppleID request -- but it keeps filling in the ID with my father's (nonexistent) iCould email. The first time I corrected the login, I ended up having to reset his AppleID password because it wouldn't recognize the one I have on record... but when all was said and done, I was able to go back to the iTunes window and was successful in authorizing the computer (with the system saying it's #2 of the 5 I'm allowed to have on the same ID).

However, immediately after telling me the computer was authorized, iTunes immediately popped up the same "not authorized" message, and every time since then (even after a restart) I get stuck in the same loop of "not authorized" - "already authorzed" - "not authorized" ad infiniyum. HELP!