title: AdMob onFailedToReceiveRefreshedAd not being called
body: <p>I am using AdMob in my Android application and want to display a backup ad if AdMob doesn't fill.  I hook into the <code>_adView.setAdListener(</code> but when no ad is returned, <code>onFailedToReceiveAd</code> does not fire like I would expect it to.  When an ad is returned, <code>onReceiveAd</code> fires, so I know I am hooked up correctly.    LogCat tells me: "No fill.  Server replied that no ads are available." which seems correct.  Any ideas?</p>
  
  <p>public class MultipleAdView extends LinearLayout {</p>
  
  <pre><code>private AdView _adView = null;
  private WebView _webView = null;
  private Context _context = null;
  
  /*
   * Constructor from parent class.
   */
  public MultipleAdView(Context context) {
      super(context, null);
  
      _context = context;
  }
  
  public MultipleAdView(Context context, AttributeSet attrs){   
      super(context, attrs);
  
      _context = context;
  }
  
  public void initialize(Activity activity){
      _adView = new AdView(activity);
      _adView.setAdListener(new AdListener() {
  
          @Override
          public void onReceiveRefreshedAd(AdView arg0) {
              int j = 0;
              j++;
          }
  
          @Override
          public void onReceiveAd(AdView arg0) {
              // Just here for breakpoint - gets in here fine when ad is returned
              int j = 0;
              j++;
          }
  
          @Override
          public void onFailedToReceiveRefreshedAd(AdView arg0) {
              // Is never called when no ad is returned
              loadBackupAd();
          }
  
          @Override
          public void onFailedToReceiveAd(AdView arg0) {
              // Is never called when no ad is returned
              loadBackupAd();
          }
  
          private void loadBackupAd(){
  
              // Load backup ad here
          }
      });
  
      addView(_adView, new LinearLayout.LayoutParams(
              LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));
  
  }   
  </code></pre>
  
  <p>}</p>