title: Exception using HttpRequest.execute(): Invalid use of SingleClientConnManager: connection still allocated
body: <p>I'm using google-api-client-java 1.2.1-alpha to execute a POST request, and am getting the following stacktrace when I execute() the HttpRequest.  </p>
  
  <p>It happens immediately after I catch and ignore a 403 error from a previous POST to the same URL, and re-used the transport for the subsequent request.  (It's in a loop inserting multiple entries to the same ATOM feed).</p>
  
  <p>Is there something I should be doing to 'clean up' after a 403?</p>
  
  <pre><code>Exception in thread "main" java.lang.IllegalStateException: Invalid use of SingleClientConnManager: connection still allocated.
  Make sure to release the connection before allocating another one.
      at org.apache.http.impl.conn.SingleClientConnManager.getConnection(SingleClientConnManager.java:199)
      at org.apache.http.impl.conn.SingleClientConnManager$1.getConnection(SingleClientConnManager.java:173)
      at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:390)
      at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:641)
      at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:576)
      at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:554)
      at com.google.api.client.apache.ApacheHttpRequest.execute(ApacheHttpRequest.java:47)
      at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:207)
      at au.com.machaira.pss.gape.RedirectHandler.execute(RedirectHandler.java:38)
      at au.com.machaira.pss.gape.ss.model.records.TableEntry.executeModification(TableEntry.java:81)
  </code></pre>
  
  <p>Why would the code below me be trying to acquire a <em>new</em> connection?</p>