We had a really peculiar bug that was discovered just as we were about to deliver a final drop of an app that we developed for a client.
The app is intended to run on iPad and iPhone — its a universal app. The problem was that although the app ran fine on the iPad and iPhone, it did absolutely nothing on the iPod touch. The app would just turn the iPod touch screen black and then do nothing. It didn’t crash. It didn’t generate memory warnings and get booted from springboard by the OS. Nothing. Nada. Zilch.