sharedlibrary apply-load-rules all
dyld: Library not loaded: /System/Library/Frameworks/iAd.framework/iAd
  Referenced from: /var/mobile/Applications/512A1A74-FEB0-4744-B5E1-E90BA231ED30/
  Reason: image not found


iAds framework is only available on iOS 4.0 or greaer, so check the iOS version of the of the target device to make sure it is runing 4.0 or higher.

Alternatively you can weak link the iAd.framework using the compiler directive or marking iAd.framework as optional via the project lib settings, in this way it will not error out in iOS versions which are less than 4.0 too.