problem during restart async. TCP server ??

[Ikado]

I have an async. tcp server, I want to restart it in some periods.
but there is a problem
I am closing all sockets,
Initializing new IPEndPoint and binding it,
I am creating a new listening socket,
And it continues with
Client.Listenin gSocket.BeginAc cept(new AsyncCallback(O nClientConnect) , null);
It works normally when any client is not trying to connect..
But when any client try to connect during restart I got an exception in Onclientconnect line,
Socket ActiveSocket = Client.Listenin gSocket.EndAcce pt(asyn);
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Cannot access a disposed object.
Object name: 'System.Net.Soc kets.Socket
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or
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Object reference not set to an instance of an object.
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pls help,