title: Advert layout incorrectly opening from modal
body: <p>I've taken over development of an iPad app and am adding AdMob into it, this is all working correctly apart from one layout issue when the advert opens, I believe it may be to do with it opening from a modal window.</p>
  
  <p>The advert opens with some content from the previous window infront of it, it covers the status bar, and leaves a space at the bottom about the same height as the status bar. I'm adding this advert in the same way I am the others, which work from...</p>
  
  <pre><code>GADAdSize customAdSize = GADAdSizeFromCGSize(CGSizeMake(300, 50));
  adView = [[DFPBannerView alloc] initWithAdSize:customAdSize];
  adView.adUnitID = @"xxxxxxxxxxxx";
  adView.rootViewController = self;
  [self.view addSubview:adView];
  [adView setDelegate: self];
  </code></pre>
  
  <p>Any ideas how this can be fixed, without restructuring the app so the previous one isn't a modal window?
  <img src="https://i.stack.imgur.com/iBD2s.png" alt="This is how it looks when the advert opens"></p>