I had a similar problem recently. Browsing and adding the printer didn't work, but manually entering \\computername\sharename did work. You don't need to add a local port, but this is an option open to you.
Most of the shared printers (usually connected to a PC via usb or other) are listed in the AD. They are happily working with the PC they are connected to and usually some others in the same locale. But now when you try to add that printer to a different PC the following error is reported: "Windows cannot connect to the printer. Either the printer name was typed incorrectly, or the specified printer has lost its connection to the server. For more information, click Help."