title: Handling Unbalanced calls to begin / end appearance when popping controller
body: <p>I'm trying to add some error handling (to cope with loses of network connectivity when initializing my view models as well as elsewhere) by having it publish a message that is picked up by my view models that will then do a <code>ChangePresentation</code> with a <code>PresentationHint</code> that causes my presenter (derived from <code>MvxTouchViewPresenter</code>) to do this:</p>
  
  <pre><code>this.MasterNavigationController.PopToRootViewController(false);
  </code></pre>
  
  <p>This occasionally works, but a lot of the time it doesn't, getting stuck on whatever view it was currently on and I see the message <code>Unbalanced calls to begin/end appearance transitions for &lt;MyView: 0x...&gt;</code>. I believe this is because sometimes the message is getting thrown before the view that was loading has had time to finish loading (the actual loading of data is asynchronous and fires up on another thread - hence the problem).</p>
  
  <p>So my question is, is there a way to synchronize this so that instead of immediately popping to the root, it will finish what it's doing, then pop to the root? Or is there some better way to handle this? </p>