Minidlna Server Stops Responding

Question

minidlna starts up and will serve media OK. However, after a period of time it stops responding - clients can't see the server. Restarting it fixes the problem for a while, until it stops responding again. I have logging turned up to max, but no errors are shown apart from the ones shown below when it first starts up.
[2013/07/02 10:20:42] minidlna.c:885: warn: Starting MiniDLNA version 1.0.25 [SQLite 3.7.16.2].
[2013/07/02 10:20:42] minissdp.c:72: error: setsockopt(udp, IP_ADD_MEMBERSHIP): Address already in use
[2013/07/02 10:20:42] minissdp.c:122: warn: Failed to add multicast membership for address 192.168.0.66
[2013/07/02 10:20:42] minidlna.c:991: warn: HTTP listening on port 8200

Answer 1

I had the same issue when I was using a semi-managed network switch, which could understand multicast traffic. It tracked the IP_ADD_MEMBERSHIP and IP_DROP_MEMBERSHIP requests, so that multicast traffic would only be sent to those ports, that have joined the multicast group before. The problem was, that there was some kind of timeout after which the switch forgot about the joins, so that the multicast packets weren't sent to any port, because there was seemingly no one listening.
I replaced it with an unmanaged switch that handles multicast packets like broadcast, sends them to all ports and have the clients throw them away, if they are not interested