Remoting server does not really unregister the channel?

Question

Hi, sorry about my bad english. I have written a small chat witch uses remoting tech. I use the client-activated server-object, TCP-Channel and singleton. The communication works fine, but on stop-server-method I call the ChannelServices.UnregisterChannel(channel); method. This should be close the communication-port. No client should be logon to the downed but running server. But I could it. I tested it. The channel is min. 15 sec. open after I unregister them. What happens? Anyone ideas? Asterix