title: Application crash on presentmodalviewcontroller
body: <p>This is strange.. My app worked good before I duplicated the target to make a paid version of my app.. When I want to show a UIViewController, it is loaded, and shown, but my application crashes, and gives me this error in the device log:</p>
  
  <pre><code>Thread 0 name:  Dispatch queue: com.apple.main-thread
  Thread 0 Crashed:
  0   libobjc.A.dylib                 0x341c2fbc objc_msgSend + 16
  1   UIKit                           0x3735fdfe -[UINavigationController topViewController] + 46
  2   UIKit                           0x37395ae4 -[UINavigationController viewDidDisappear:] + 80
  3   UIKit                           0x373636ae -[UIViewController _setViewAppearState:isAnimating:] + 138
  4   UIKit                           0x373beaea -[UIViewController _endAppearanceTransition:] + 258
  5   UIKit                           0x373ecec8 -[UIViewController endAppearanceTransition] + 16
  6   UIKit                           0x3741cf04 -[UIWindowController transitionViewDidComplete:fromView:toView:] + 1404
  7   UIKit                           0x373bc934 -[UITransitionView notifyDidCompleteTransition:] + 140
  8   UIKit                           0x373bc7b8 -[UITransitionView _didCompleteTransition:] + 896
  9   UIKit                           0x37336814 -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 464
  10  UIKit                           0x3733bfb2 -[UIViewAnimationState animationDidStop:finished:] + 46
  11  QuartzCore                      0x34a8dba0 CA::Layer::run_animation_callbacks(void*) + 196
  12  libdispatch.dylib               0x36bace86 _dispatch_main_queue_callback_4CF$VARIANT$up + 190
  13  CoreFoundation                  0x33f4b2d6 __CFRunLoopRun + 1262
  14  CoreFoundation                  0x33ece4d6 CFRunLoopRunSpecific + 294
  15  CoreFoundation                  0x33ece39e CFRunLoopRunInMode + 98
  16  GraphicsServices                0x30752fc6 GSEventRunModal + 150
  17  UIKit                           0x3734f73c UIApplicationMain + 1084
  18  MyApp                       0x00002674 main (main.m:15)
  19  MyApp                       0x00002624 start + 32
  </code></pre>
  
  <p>Where is my error? Can anyone help me?</p>