Itunes says my ipod has 5 authorized computers, this is not true. Help?

I can not transfer my itunes purchases onto my newer comp from my old nano. It asks me to authorize my computer and then states that my new comp is authorized, but when I go to actually transfer content, itunes tells me that my ipod is already maxed out and will not allow for the transfer. When I look under my apple ID, there is only one computer that is authorized.