LiveMessenger generating tons of network activity

I'm having a problem with LiveMessenger generating an unusual amount of network traffic - the animated network activity icon stays on most all the time when LiveMessenger is running. I've run TCPView and see that LiveMessenger fires up dozens of TCP connections for System Process 0 - the remote address is always "192.168.0.1:5678" and the status is TIME WAIT, and the local address is mycomputer:nnnnn where nnnnn is a random number. As I watch, some of the older connections will drop off and new ones with the same remote address will pop up, but the number of total connections slowly grows. When I exit from LiveMessenger, these connections will slowly go away and the network activity icon returns to normal appearance.

I use AVG Internet Security Suite and everything's up to date, but it sure sounds like a virus - any ideas?
thanks,
steve