2013-10-22 14:01:51.462 Mosayc[2324:a0b] nested push animation can result in corrupted navigation bar
2013-10-22 14:01:51.814 Mosayc[2324:a0b] Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted.
2013-10-22 14:01:51.904 Mosayc[2324:a0b] Unbalanced calls to begin/end appearance transitions for <UIViewController: 0xac84140>.
2013-10-22 14:04:30.161 Mosayc[2324:a0b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Can't add self as subview'
*** First throw call stack:
(
	0   CoreFoundation                      0x028775e4 __exceptionPreprocess + 180
	1   libobjc.A.dylib                     0x025fa8b6 objc_exception_throw + 44
	2   CoreFoundation                      0x028773bb +[NSException raise:format:] + 139
	3   UIKit                               0x0127f96b -[UIView(Internal) _addSubview:positioned:relativeTo:] + 113
	4   UIKit                               0x01273521 -[UIView(Hierarchy) addSubview:] + 56
	5   UIKit                               0x0120c376 __53-[_UINavigationParallaxTransition animateTransition:]_block_invoke + 1701
	6   UIKit                               0x01279f5f +[UIView(Animation) performWithoutAnimation:] + 82
	7   UIKit                               0x0120b8a6 -[_UINavigationParallaxTransition animateTransition:] + 1155
	8   UIKit                               0x013464de -[UINavigationController _startCustomTransition:] + 3446
	9   UIKit                               0x01352757 -[UINavigationController _startDeferredTransitionIfNeeded:] + 688
	10  UIKit                               0x01353349 -[UINavigationController __viewWillLayoutSubviews] + 57
	11  UIKit                               0x0148c39d -[UILayoutContainerView layoutSubviews] + 213
	12  UIKit                               0x01282dd7 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 355
	13  libobjc.A.dylib                     0x0260c81f -[NSObject performSelector:withObject:] + 70
	14  QuartzCore                          0x00fe072a -[CALayer layoutSublayers] + 148
	15  QuartzCore                          0x00fd4514 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380
	16  QuartzCore                          0x00fd4380 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 26
	17  QuartzCore                          0x00f3c156 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 294
	18  QuartzCore                          0x00f3d4e1 _ZN2CA11Transaction6commitEv + 393
	19  QuartzCore                          0x00f3dbb4 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 92
	20  CoreFoundation                      0x0283f53e __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 30
	21  CoreFoundation                      0x0283f48f __CFRunLoopDoObservers + 399
	22  CoreFoundation                      0x0281d3b4 __CFRunLoopRun + 1076
	23  CoreFoundation                      0x0281cb33 CFRunLoopRunSpecific + 467
	24  CoreFoundation                      0x0281c94b CFRunLoopRunInMode + 123
	25  GraphicsServices                    0x041fb9d7 GSEventRunModal + 192
	26  GraphicsServices                    0x041fb7fe GSEventRun + 104
	27  UIKit                               0x0121894b UIApplicationMain + 1225
	28  Mosayc                              0x0003d651 main + 177
	29  libdyld.dylib                       0x02e9b725 start + 0
)
libc++abi.dylib: terminating with uncaught exception of type NSException