title: AdMob crashes with [GADObjectPrivate changeState:]: unrecognized selector
body: <p>I have installed the AdMob SDK 6.2.0 (Xcode 4.5 (4G182) and I am testing on an iPhone 4S and the simulator). I followed the tutorial and just want to get AdMob showing a banner once. But it crashes on the last line:</p>
  
  <pre><code>self.bannerView = [[GADBannerView alloc]
                 initWithFrame:CGRectMake(0.0,
                                          self.view.frame.size.height -
                                          GAD_SIZE_320x50.height,
                                          GAD_SIZE_320x50.width,
                                          GAD_SIZE_320x50.height)];
  
  self.bannerView.delegate = self;
  self.bannerView.adUnitID = @"xREMOVEDBYMEx";
  self.bannerView.rootViewController = self;
  [self.view addSubview:self.bannerView];
  GADRequest * request = [GADRequest request];
  request.testing = YES;
  [self.bannerView loadRequest:request];
  </code></pre>
  
  <p>The crash is</p>
  
  <blockquote>
    <p>2012-09-28 09:03:58.268 NewProject[1467:c07] -[GADObjectPrivate changeState:]: unrecognized selector sent to instance 0x95c17d0
    2012-09-28 09:03:58.276 NewProject[1467:c07] <em>*</em> Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[GADObjectPrivate changeState:]: unrecognized selector sent to instance 0x95c17d0'</p>
  </blockquote>
  
  <p>This looks like a bug in the library to me but I think thats very unlikely. Any thoughts?</p>
  
  <p>EDIT: The exact same code works in the example projects. Is there something I can do wrong with my project file that would result in that error?</p>