title: Is it a problem when an iAd may be obscured?
body: <p>I added the ADBannerView to a view and when I load the app I get the following message:</p>
  
  <p>ADBannerView: WARNING A banner view (0x7a023c0) has an ad but may be obscured. This message is only printed once per banner view.</p>
  
  <p>As far as I can see the entire banner is visible on the screen. Is this really a problem? Or is it only a warning that I can ignore?</p>