During instantiation of the client, a MessageStreamListener is created. Inside of the listener is a call is made to the config url
Line 376 of MessageStreamListener
this.request = this.requestFactory.GetWebRequest(configUrl, configUrl.GetHashCode().ToString());
this.response = this.request.GetResponse();
If this call never completes, for example because AVG silently blocks the request and prevents the data from being returned, then the client will wait indefinitely instead of timing out.