TV: Brand new 46PFL9706
Router: Sitecom AA737C
PC: Windows XP with WMP11 installed and activated and WiFi Media connect software installed and activated. Protected with ESET Smart Security (Virus and Firewall)

The TV connects fine to the internet via WiFi, e.g. can access media via NetTV, download movies etc.
The PC is connected to the internet via the same wireless router as the TV

So far so good but, now the PC keeps looking for a TV on the network forever without finding a TV and the TV keeps looking for a media server on the network without finding one.

Same problem with Dell laptop (Windows XP).

Philips support desk doesn't have a clue, recommends to instal new firmware, buy a new router (without telling me which one) and if that fails buy a new PC. Can anyone on the forum help me? I am guessing it must be some setting in the router, but there are too many to just try some out. If you have a recommendation please be specific in instructions as I am not someone who's hobby it is to solve computer connectivity problems and therefore don't assume I understand the geek words or abbreviations.