troubleshooting
I looked at the manual for that model. It doesn't look like that router allows you to set up your own packet filters. I guess I just assumed it did. You'll definately want to set up a firewall on your server if there is no packet filter on the router. I've included a checklist of troubleshooting questions, please don't feel insulted by the simplicity of some of them, sometimes we all miss the little things.
Is the DHCP server enabled on the router?
-Yes
--Did you reserve the server's IP address in the DHCP Server Settings?
--Is your server set up as a DHCP client?
--You might also try disabling DHCP and setting up your server with a static IP (see below)
-No
--Did you manually set the DNS addresses of your ISP on your server?
Does your ISP for some reason block that port (and others)? They don't normally, but it is possible.
~~~)-Steven----
"I want you to remember that no bastard ever won a war by dying for his country.
He won it by making the other poor dumb bastard die for his country..."
General George S. Patton