In my experience, D-Links are best port forwarded.
PortForward.com - Free Help Setting up Your Router or Firewall & look down left column near bottom for your model. Although Phex is not on the list, choose LimeWire but ignore the first part about LimeWire settings. The very first step & most important step is setting up a static ip;
Setting up a Static ip & then follow the port forward instructions however use the port you have set for Phex, not the one shown for LimeWire. After this process, save your settings. Some D-Link routers you need to reboot them to help save & get the changes into action.