I'd suggest your D-Link is probably the fault. I also use a D-Link & was forced to forward a port. I believe this is what you need to do. See
Port Forwarding for the Dlink DI-524 (click on link) & don't forget to save settings in the D-Link & reboot the D-Link to get the changes into action.

Oh & the most important step is the 1st one, setting up a static ip. Also, it's best to do a separate port forward for each of UDP & TCP instead of choosing All or Both.
Edit: Also see
http://www.gnutellaforums.com/showth...ght=windstream & search windstream on the forums just in case.