i have netgear d834g and it allows me to forward several ports as defined in the firewall rules.

to allow for the 585 to forward port properly:

1. telnet and login as administrator
2. firewall
3. config state=disabled
4. saveall
5. exit

now go back to the web interface and setup your port forwarding. the only trouble i have with this kind of router (tested two, so far) is that it blocks the port after sometime (no specific interval) and i have to do the above steps again, removing and adding the services and ports. so yes, it's a headache.