title: No return of "yield return WWW" method in the second run
body: <p>I'm tracking the following method in Unity3D environment:
   (called through StartCoroutine)</p>
  
  <pre><code>private IEnumerator post(string s) {
      Debug.Log("Posting to Server: " + s);
  
      WWWForm form = new WWWForm();
      form.AddField("data", s);   
  
      WWW yaPoster = new WWW(YMCA_URL,form);  
  
          Debug.log("11111");     
          yield return yaPoster;  
          Debug.log("22222");
  
          if(yaPoster.error != null) {  
              Debug.Log(yaPoster.error);
          }  
          else {  
              Debug.Log(yaPoster.text);
          }
  
      yaPoster = null;    
  }   
  </code></pre>
  
  <p>It works well for every first time (saw yaPoster.text from log console), but never can see the "11111" or "22222" in the followed calls.</p>
  
  <p>(Not) surprisingly, things run well on my iPod device with the built iOS Xcode project.</p>
  
  <p>Any specific settings I should apply for my Unity3D environment so that I don't need to debug my code only with the real device?</p>