title: facebook, android java.lang.IllegalStateException: Cannot execute task: the task is already running
body: <p>After login I can I can make FB queries. After few minutes (played game) Facebook requests fail exception:</p>
  
  <pre><code>java.lang.IllegalStateException: Cannot execute task: the task is already running
  </code></pre>
  
  <p>It fails when I call </p>
  
  <pre><code>        Request.executeMeRequestAsync(Session.getActiveSession(),
                  new Request.GraphUserCallback() {...
  
          Request.executeGraphPathRequestAsync(Session.getActiveSession(),
                  "me/apprequests", new Request.Callback() {...
  
          Request request = new Request(session, "me/apprequests", null,
                      null, new Request.Callback() { .... } );
          RequestAsyncTask status = request.executeAsync();
  </code></pre>
  
  <p>Same calls are called immediately after login and they work.
  I have a test app where it works. But in real app after few minutes after login it does not work.</p>