WCF and godaddy port forwarding

Question

I have a WCF web service running under IIS 7 with a static IP address: 173.1.1.1:9100

I set up a domain name using godaddy.com and forwared to my static ip address/port: mydomainname.net.

I have a client test app that works when I use the ip/port address, but not the godaddy domain name.

I can bring up the service description in a browser using the domain name, just can't get the service to work using it.

Any ideas are greatly appreciated.

Thanks