I had the same problem with disconnects. I have my PC, Samsung blu-ray, and a xbox360 wired to my 2wire router. I use Serviio to DLNA stream my PC's video to the Samsung blu-ray. When I changed my IP address's to static instead of DHCP, all my disconnect problems disappeared. I know it doesn't make much sense, since my renew time for DHCP was set for 1 week. Just go into your network settings of your TV, Xbox, etc and change the settings to static IP.
Also, I've noticed various brands of anti-virus can affect DLNA streaming.