Android: Screen goes black behind interstitial ad while it slides in

I show interstitial ads in my app, and I have defined a translation animation that开发者_如何学C is set to slide the ad in from right to left. The ad slides in just fine, but when the animation starts, the underlying Activity becomes completely black while the ad slides in. I would like to be able to see the underlying Activity and have the ad slide in over it. How do I keep the underlying Activity from being covered with black?

Ok, I figured it out. In case you too run into this problem, I was setting a layoutanimation on the view. I switched to just starting the animation using view.startAnimation, and the black background went away.