For rdar://13133715 filed 01-Feb-2013 06:08 PM @ https://bugreport.apple.com also at http://openradar.appspot.com/radar?id=2651401
Example code to recreate crash when inserting/deleting UICollectionView items while keyboard/first responder view showing.
Tested iOS 6.0.1 and 6.1 on device and simulator