Hi guys,
I've got the same problem, stupidly was trying to help couple of me friends creating Apple IDs for them on my iPhone. I can't create a new Apple ID on this device (I reached my limits) and I can't even use an account that I've already got (after creating it on my PC).
Ohkt's problem is that he's not creating a new Apple ID, he's just trying to use an Apple ID he's already got but can't use it on this particular device because 3 Apple IDs have been created in it by its previous user/owner.
I did a regirous search on this and haven't found a solution but perhaps going to Apple store and ask them to help you about that. I still can't see how relevant however waiting for 90 days before you can use or create an Apple ID on this particular device. Well, Bollox is the word for this ...
Cheers