Problems exposing a web site from behind a router

I have a D-Link DSL-2650U ADSL router for my home network.

I also have my own domain server registered at dyndns.org, and I have successfully configured my router to keep [mydomain].dyndns.org pointing at my router's public IP address.

I have also successfully used NAT to redirect Windows Remote Desktop calls to the desired computer.

Now I'm setting up a web site on one of the computers in my network, and I want all HTTP requests sent to [mydomain].dyndns.org to be forwarded on to that computer. Should be easy, right? But it doesn't seem to work. My web site is set up on port 800, so I set up NAT to forward calls on port 800 to my local computer. Try browsing to http://[mydomain].dyndns.org:800, and it doesn't recognize the address. I tried forwarding port 80 to port 800 on the local computer, and when I navigate to http://[mydomain].dyndns.org, instead of going to that web page, it goes to the router's admin page.

It seems that the router is ignoring the NAT setting for port 80 (and 800 for that matter) - what's the secret switch to get this working?

Try doing this from a computer outside your own network. Most routers don't resolve internal/your own domains/IP's.

Check if there is a setting to disable external (from outside your network) remote access to your router's admin panel. And do recheck the NAT forwarding.

EDIT: Plus, you might also have to wait for the DNS settings to propagate through all the networks - it usually takes half an hour to hour and a half. And usually people don't touch their router's NS settings just letting the system automatically adjust to what's on the 'Net