I\'ve written an IP multicasting application in C#. It compiles fine, but at runtime this line:
sock.SetSocketOption(SocketOptionLevel.IP,
This seems to happen when you run out of resources (sockets?) or memory. At the command prompt run: netstat -ab
I'm not sure off hand what the socket limit is. I'm currently fighting an issue like this myself.
Notes on socket limits: http://support.microsoft.com/kb/196271