title: iOS 5 -- presentModalViewController nils parentViewController in "self"?
body: <p>I'm still trying to figure out some iOS 5 vs iOS 4 problems in this incredibly (and unnecessarily) complicated app.</p>
  
  <p>I've traced one problem down to the fact that a controller (which happens to be the navigation controller of the calling class) has a <code>parentViewController</code> attached prior to being "sent" a presentModalViewController request, but on the other side of that (in <code>viewWillAppear</code> of the "presented" controller -- haven't even returned from the call) the navigation controller (I've verified that it's the same address) suddenly has a nil <code>parentViewController</code>.</p>
  
  <p>I'm reasonably certain that this behavior did not occur in iOS 4 (I've been ping-ponging back and forth between the two versions to verify behaviors).</p>
  
  <p>The code is far too complicated to include here, but the call is:</p>
  
  <pre><code>[self.navigationController presentModalViewController:messageViewController animated:[self isAnimated]];
  </code></pre>
  
  <p>There are assertions prior to the call that the <code>parentViewController</code> of the nav ctlr is non-nil, and likewise in <code>viewWillAppear</code>.  The assertion only fails in <code>viewWillAppear</code>.</p>