all right, everything you said showed up on my DI-614+ screen.
i filled out the info for all 3 ports.
on the firewalls screen, all 3 of them show up under firewall Rules list
they say
Allow Xbox live 1 LAN,* LAN,192.168.0.1 TCP, 3074; UDP 88; and UDP 3074
yet my NAT settings still says...