title: MixPanel: Users showing as guests in the report
body: <p>I have been trying to integrate Mixpanel into my Android app. The things works fine when it comes to tracking events and such, but the problem is that all the events are recorded under a single guest in the report. 
  I called identify() on both the <code>mixpanel.identify()</code> and <code>mixpanel.getPeople().identify()</code> and my code looks something like this: </p>
  
  <pre><code>    MixpanelAPI mixpanel = MixpanelAPI.getInstance(this, MIXPANEL_TOKEN);
      MixpanelAPI.People people = mixpanel.getPeople();
      people.identify("666");
      people.set("first_name", "john");
      people.set("last_name", "smith");
  
      JSONObject props = new JSONObject();
      try {
          props.put("Gender", "Male");
          props.put("Plan", "Premium");
      } catch (JSONException e1) {
          // TODO Auto-generated catch block
          e1.printStackTrace();
      }
  
  
      mixpanel.track("Plan selected", props);
      mixpanel.flush();       
  </code></pre>
  
  <p>No matter how many times that tracking event got sent (even if i change the value of the identify and track again), all the event are tracked under a random guest name : Guest #74352</p>