title: zmq subscriber fails to receive message when subscriber is restarted
body: <p>I have <strong><code>PUB/SUB</code></strong> program using <code>zmq</code> broker ( <code>node.js</code> ).</p>
  
  <p>Subscriber <strong>doesn't</strong> receive messages while subscriber is restarted and publisher is still publishing the messages. But <code>PUB/SUB</code> is working fine when both publisher and subscriber services are started naturally. Reason behind this is unknown.</p>
  
  <p><strong>What could possibly be wrong?</strong></p>