That does sound weird that it works for a while and then stops. A few things to check: (i) check if your router has UPnP built-in features (turn them off), (ii) check if your router has a built-in firewall (turn it off), (iii) check if your router has IGMP snooping (turn it off), (iv) check if you are running Hamachi on your PC (uninstall it). Also, reboot your router. As a test, if you have another DLNA device in your home (PS3, Xbox 360, etc.) , see if it has the same disconnect problem - that will help isolate it to your TV or your home network/PC/DLNA server being the culprit. Good luck!
XP, BT Home Hub, wired connection to Samsung LE40D580K2K tv.
Samsung ShareAll installed on my pc, the tv very rarely sees the connection to my pc, after several days of not seeing the pc, I switch the tv on and AllShare connects, the connection works for about 15 mins then get "device disconnected" on the tv. Have not really timed the connection but approx 15 mins seems consistent. Tried serviio, tv will connect every time it is switched on but in this case it only stays connected for 7 minutes. Only way to get it to reconnect is to swith tv off and on. After tv has disconnected, router still says tv is online, network status check on tv shows all ok.
Have set static address for the tv and disabled firewall but it has not made any difference. At present have uninstalled serviio and have Samsung AllShare running. Please note I am new to connecting tv to pc so not very technical about the subject.