title: Custom fragment transition animation not playing correctly when I pop the BackStack
body: <p>I'm inserting Fragments into the Activity using this code:</p>
  
  <pre><code>FragmentTransaction transaction = getFragmentManager().beginTransaction();
  
  MyFragment myFragment = new FMyFragment();
  transaction.setCustomAnimations(R.anim.fade_in, R.anim.fade_out);
  transaction.replace(R.id.DetailsFragment, myFragment, ForumCreateFragment.FRAG_TAG);
  transaction.addToBackStack(null);
  
  transaction.commit();
  </code></pre>
  
  <p>The custom transition animation is a simple fade in/out animation. It's displaying correctly when I just add this same type of Fragment multiple times.</p>
  
  <p>But when I pop the fragment-backstack with the back button, it flashes in the previous fragment, fades it away, and leaves a blank area, displaying nothing - even if there are more elements on the backstack. It seems that popping the stack causes the transition animations to play backwards. What am I doing wrong?</p>