you have to assign printserver-adress to internet port
however - different to xp - vista x64 doesn't allow for that
to workaround add a network printer first and assign the full network path (... /printers/My_Printer)
next add another, local printer and forward it to internet port. Vista to this port then will automatically add the network path created during previous step.
please note there might occur error messages. simply click away.
