I have a 42PFL6007T/12 on which DLNA does not work.
Initially it did work for one video, but after 30 seconds it suddenly stopped working and hasn't worked since.

What I have done:
1) The TV is connected by cable to the router and has a confirmed fast connection to internet (confirmed IP in TV settings, confirmed by TED talk SmartTV app streaming video, checked by pinging the TV and getting fast response, and by entering router and seeing that it can see the TV)
2) Have enabled all media sharing options available on windows and windows media player, temporarily turned off the antivirus and firewall, ensured that I have shared files in the media library
3) Can see my own computer in the network as a media device

What isn't working:
1) the TV can't find the media server (gets stuck on the first screen that says "switch on your computer and start the media server application...")
2) The computer can not see the TV in the network (despite that it can reach it when pinging)

Additional info
- TV: 42PFL6007T/12
- Software: QF1EU-
- TV is plugged into router via network cable.
- Confirmed fast connection by pinging via computer connected to router (reply <2ms)
- Media server programme: Windows Media Player 12
- WNR3500L RangeMax Wireless-N Gigabit Router

I am now considering to return the TV in pure disappointment and frustration - despite my initial plan to post a positive review.. Could someone please advice me on what I ought to do?