No I don't have any idea.
You could check services.msc
from start menu search box. Copy and paste that to it, hit enter. Look to see that SSDP discovery is set to automatic and running. Do the same for Media Center Extender Service.
If you're running into lots of problems as it seems, I recommend using TVeristy
as a superior (imho) alternative.
If you do, after installing, go back to services and disable the following:
UPnP Device Host
Windows Media Player Network Sharing Service