I can't assist with router settings, but are there any time-out functions in the router itself? You might try to seek some additional information at C|Net's Networking forum - there are some pretty smart networking guys who participate often.
If you're interested, that can be found here:
I'm sorry, but I don't know how to assist further.
the network connection (ethernet cable) is working for approximately 5 minutes after which the tv cannot be reached in the network anymore (ping, DLNA discovery etc.). The Network Settings must be set to Manual and all tests are correct. Setting to Auto sometimes works but mostly does not which is a bit strange.
The result of this issue is that I can use Internet@TV (Widgets) or DLNA only for this short timeframe (3 minutes).
To be sure that it is not a router-based problem I connected the tv directly to the PC via ethernet cable and assigned an IP manually. The same problem occurs - after approx. 3 Minutes the TV does not respond (to network pakets) anymore.
I'm using firmware 1008 and have also tried the former version 1007 with no luck.
Hopefully someone could give me a hint what's wrong and tell me how to overcome the issue.