title: Weird behavior of hidesBottomBarWhenPushed = YES (moves views when popping back)
body: <p>So I've got something really weird going on here, and can't quite put my figure on it.  Basically, I've got a view that has two subviews: one is to a webview, the other is to a button controller</p>
  
  <p>See here for the bug:  <a href="http://screencast.com/t/zTjAUP8aXgz" rel="nofollow">http://screencast.com/t/zTjAUP8aXgz</a></p>
  
  <p>Now when I pushViewController to another controller and pop back, everything works fine, <em>except</em> when I pushViewController to a certain view controller (the one with the magnifying glass).  When I do that, I see the following bugs:</p>
  
  <ol>
  <li>the webview gets 20 pixels shorter</li>
  <li>the button controller gets pushed up 7-8 pixels.</li>
  </ol>
  
  <p>I've isolated it down to the fact that when the tab bar is hidden (with hidesBottomBarWhenPushed = YES), the bug is no longer seen:</p>
  
  <p><a href="http://screencast.com/t/VARgPr4u" rel="nofollow">http://screencast.com/t/VARgPr4u</a></p>
  
  <p>What could cause this?  Is it a bug in hidesBottomBarWhenPushed ?  If so, how can I compensate for it?</p>