iAd left white blank screen after closed

Question

I got a problem to integrate iAd in my iPhone apps -- the banner ad is fine when it expends (see http://www.clingmarks.com/iAd1.png and http://www.clingmarks.com/iAd2.png),

Answer 1

Eventually I figured it out myself. It turns out the ADBannerView's parent view must be a fullscreen view. I my case above, I added AdBannerView to my adView, which is a view with size 320x50. When I changed its parent view to a fullscreen view, everything works. I am not sure if this is a bug in iAd, but certainly something tricky.