iAd在iOS4.3中崩溃

Question

尝试在具有多个不同视图控制器的通用应用程序中实现iAd，尝试实现Apple的iAd套件中的示例代码，既是单个视图控制器中的基本代码，也是单独使用导航控制器代码，都会导致崩溃是指在nil时添加到字典中的pngData。视图控制器中没有字典，也没有任何名为pngData的字典。 这是堆栈跟踪 -

2012-03-14 15:24:24.389 TheApp[11372:207] CRASH: -[__NSCFDictionary setObject:forKey:]: attempt to insert nil value (key: pngData)
2012-03-14 15:24:24.390 TheApp[11372:207] Stack Trace: (
    0   CoreFoundation                      0x0328f5a9 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x030be313 objc_exception_throw + 44
    2   CoreFoundation                      0x03247ef8 +[NSException raise:format:arguments:] + 136
    3   CoreFoundation                      0x03247e6a +[NSException raise:format:] + 58
    4   CoreFoundation                      0x0328de15 -[__NSCFDictionary setObject:forKey:] + 293
    5   iAd                                 0x001a0cd8 -[ADBannerController executeBannerViewActionFrom:withClickLocation:] + 422
    6   iAd                                 0x001914d8 -[ADBannerView touchesEnded:withEvent:] + 355
    7   UIKit                               0x00497ded -[UIWindow _sendTouchesForEvent:] + 567
    8   UIKit                               0x00478c37 -[UIApplication sendEvent:] + 447
    9   UIKit                               0x0047df2e _UIApplicationHandleEvent + 7576
    10  GraphicsServices                    0x03828992 PurpleEventCallback + 1550
    11  CoreFoundation                      0x03270944 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
    12  CoreFoundation                      0x031d0cf7 __CFRunLoopDoSource1 + 215
    13  CoreFoundation                      0x031cdf83 __CFRunLoopRun + 979
    14  CoreFoundation                      0x031cd840 CFRunLoopRunSpecific + 208
    15  CoreFoundation                      0x031cd761 CFRunLoopRunInMode + 97
    16  GraphicsServices                    0x038271c4 GSEventRunModal + 217
    17  GraphicsServices                    0x03827289 GSEventRun + 115
    18  UIKit                               0x00481c93 UIApplicationMain + 1160
    19  TheApp                              0x00002039 main + 169
    20  TheApp                              0x00001f85 start + 53
    21  ???                                 0x00000001 0x0 + 1
)

就在崩溃之前，当我点击横幅时出现了一堆错误，超过50个与CGContext有关并且都非常类似于此

 <Error>:CGContextRestoreGState: invalid context 0x0
 <Error>: CGContextSetBaseCTM: invalid context 0x0
 <Error>: CGContextRestoreGState: invalid context 0x0
 <Error>: CGContextRestoreGState: invalid context 0x0
 <Error>: CGContextSetBaseCTM: invalid context 0x0

我把所有例外的断点都放在 -

int retVal = UIApplicationMain(argc, argv, nil, NSStringFromClass([TheAppAppDelegate class]));

我搜索了高低，找不到这个答案，最后一件事，它在iOS 5.0模拟器中工作正常但在iOS4.3模拟器中崩溃