iAd crashes in iOS4.3

Trying to implement iAd in a Universal App with a number of different view controllers, have tried implementing the sample code from Apple's iAd suite, both the basic in an individual viewcontroller and seperately using the navigationcontroller code, both result in a crash that refers to pngData added to a dictionary when nil. There is no Dictionary in the viewcontroller nor is there anything named pngData. This is the stacktrace-

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
)

and just before the crash, which happens when I click on the banner i get a bunch of errors, more than 50 all to do with CGContext and all pretty similar to this

 <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

I put a breakpoint all exceptions and it stops at-

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

I have searched high and low and can't find an answer to this one, one last thing, it works fine in the iOS 5.0 simulator but crashes in the iOS4.3 Simulator