title: Unrecognized selector in application didFinishLaunchingWithOptions with topViewController assignment
body: <p>What is causing this?  I am running iOS 5.1 on Xcode 4.3 and using Storyboards.</p>
  
  <pre><code>'NSInvalidArgumentException', reason: '-[WFTopTableViewController topViewController]: unrecognized selector sent to instance 0x6d56f80'
  
  
  - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
  {   
      // Initial view controller is a Table View Controller, so we look up the window's rootViewController.
      UINavigationController *navigationController = (UINavigationController *)self.window.rootViewController;
      // Set up the controller.
      WFTopTableViewController *controller = (WFTopTableViewController *)navigationController.topViewController;
      // Pass the controller the managed object context for the first time.
      controller.managedObjectContext = self.managedObjectContext;
      return YES;
  }
  </code></pre>
  
  <p>Thanks!
  Amanda</p>