are you connecting via another computer like a laptop on wireless? If so I had that same problem, could never figure it out. I am on an actiontec router.
try using your local IP address instead. make sure that in your router in the por tforwarding you have the port forwarded to the correct IP if you have more than one computer connected. Other than that im not sure what your probolem can be. I would try connection first using the local IP 192.168.0.2