Printer will not register on the Domain

My company uses color copy machines that also are used as printers. These copy machines come with their own controller that does the spooling for the print jobs. When you first install one, it automaticall comes up on the network and registers itself in the Server Mgr. We have one printer though that will not. It is on the network because we can ping it, print by ip address and the sort, but we can not attach to by the network neighborhood. We get an error that says it is not on the domain. Any ideas?