I have problems with my uPnP service too. I use it to port forward my outside connections to my internal cameras. When the router is first powered on and I run the camera software, it reports that the port is correctly forwarded. After a period of time, usually on the order of a few days, I suddenly can't connect to my cameras. If I log on to the server pc, turn off the streaming and restart it, the software reports that it can't find any uPnP devices. If I pull the power on the router, it still won't work, but if I log on to the router and do a reset from the Tools|System|Reboot the Device menu, once the reboot is complete, the software can then get a reply back from the router, and everything works again for a while.