iPhone app crashes with exception - iphone

Question

I have an iPhone app which uses iAd...The app crashes sometime with the following message;
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFType bannerViewDidLoadAd:]: unrecognized selector sent to instance 0x621cd10'
*** Call stack at first throw:
(
0 CoreFoundation 0x00e015a9 __exceptionPreprocess + 185
1 libobjc.A.dylib 0x00f55313 objc_exception_throw + 44
2 CoreFoundation 0x00e030bb -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
3 CoreFoundation 0x00d72966 ___forwarding___ + 966
4 CoreFoundation 0x00d72522 _CF_forwarding_prep_0 + 50
5 CoreFoundation 0x00d71c7d __invoking___ + 29
6 CoreFoundation 0x00d71b51 -[NSInvocation invoke] + 145
7 CoreFoundation 0x00d72a04 ___forwarding___ + 1124
8 CoreFoundation 0x00d72522 _CF_forwarding_prep_0 + 50
9 iAd 0x00[Switching to process 8860 thread 0x207]
0139f9 -[ADDistributedMessagingCenter messagePort:receivedMessage:withData:] + 251
10 iAd 0x00014012 ADMessagePortCallBack + 75
11 CoreFoundation 0x00db8f4c __CFMessagePortPerform + 396
12 CoreFoundation 0x00de2944 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
13 CoreFoundation 0x00d42cf7 __CFRunLoopDoSource1 + 215
14 CoreFoundation 0x00d3ff83 __CFRunLoopRun + 979
15 CoreFoundation 0x00d3f840 CFRunLoopRunSpecific + 208
16 CoreFoundation 0x00d3f761 CFRunLoopRunInMode + 97
17 GraphicsServices 0x033fe1c4 GSEventRunModal + 217
18 GraphicsServices 0x033fe289 GSEventRun + 115
19 UIKit 0x002ffc93 UIApplicationMain + 1160
20 MyApp 0x00001ba8 main + 102
21 MyApp 0x00001b39 start + 53
)
terminate called after throwing an instance of 'NSException'
Below is my NSZombie message;
# Category Event Type RefCt Timestamp Address Size Responsible Library Responsible Caller
77 DetailController Zombie -1 04:01.914.883 0x5768bd0 0 iAd -[ADDistributedMessagingCenter messagePort:receivedMessage:withData:]
Also bannerViewDidLoadAd code;
- (void)bannerViewDidLoadAd:(ADBannerView *)banner
{
if (!bannerIsVisible)
{
[UIView beginAnimations:#"animateAdBannerOn" context:NULL];
// assumes the banner view is offset -50 pixels so that it is not visible.
banner.frame = CGRectOffset(banner.frame, 0, -50); // if the banner is on top of the screen use 50
[UIView commitAnimations];
bannerIsVisible = YES;
}
}
Please help me fix the same. Thank you.

Answer 1

Basically you're calling bannerViewDidLoadAd: with the wrong object type. It appears that you're using some sort of dispatch mechanism to do this. Either you specified the wrong object when you set up the dispatch request for that method, or you failed to retain the object and it's been deleted and replaced with a NSType object.
So find where bannerViewDidLoadAd: is mentioned in your code and make sure the object being used with it is correct and is appropriately retained.

Answer 2

bannerViewDidLoad is getting called after it's delegate is released, hence the zombie message.
I would guess that this means your ad isn't being released and is sticking around after your controller is going away.