title: Spring integration:Header value router not getting invoked everytime
body: <p>We are using <code>header-value-router</code>. Configuration:</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;int:header-value-router input-channel="accountSummeryRequest"
          header-name="word"
          default-output-channel="accountSummeryRequest"
          resolution-required="false"&gt;
      &lt;int:mapping value="xx" channel="accountSummeryRequest" /&gt;
      &lt;int:mapping value="yy" channel="newRequestChannel" /&gt;
  &lt;/int:header-value-router&gt;
  
  &lt;int:service-activator id="accountServiceActivator" 
          input-channel="accountSummeryRequest"
          output-channel="accountSummeryResponse" 
          ref="serviceGatewayAdapter" 
          method="requestHandler" 
          send-timeout="60000"/&gt;
  
  &lt;int:service-activator id="caRequestActivator" 
          input-channel="newRequestChannel"
          output-channel="accountSummeryResponse" 
          ref="caServiceGatewayAdapter" 
          method="requestHandler" 
          send-timeout="60000"/&gt;
  </code></pre>
  
  <p>now if i give word as <code>yy</code>,first time header-value-router <code>enter code here</code>is getting called and exact service activator,in this case  is <code>caRequestActivator</code> ,is called. But i try again with <code>word=yy</code> header-value-router is not getting called and request goes through <code>accountServiceActivator</code>. Alternate requests works correctly.</p>
  
  <p>I don't know what's the problem here.</p>