Lidgren cut the disconnect string.

gistfile1.cs

NetIncomingMessage incMsg;
NetConnection sender;
while ((incMsg = server.ReadMessage()) != null)
{
  	sender = incMsg.SenderConnection;
		Client t_client = clients.GetClientFromConnection(sender);
		switch (incMsg.MessageType)
		{
				case NetIncomingMessageType.StatusChanged:
						if (sender.Status == NetConnectionStatus.Connected)
						{
								// Some instructions
						}
						else if (sender.Status != NetConnectionStatus.Connected)
						{
								if (t_client != null)
								{
										WriteOutput("[Disconnected]Client " + t_client.ClientId + " has disconnected (" + incMsg.ReadString + ")");
										clients.RemoveClient(t_client);
										OnDisconnectedClient(t_client, new EventArgs());
								}
						}
						break;
		}
}