I've hade a problem downgrading iOS 6 on a 5th gen 32gb black iPod touch it got stuck on the spinning loading icon forever. I  hade to restore it a few times then realized could not restore from backup due to the downgrade hade corrupted my back up to where it gets froze on the loading spinning thing. with the iOS 6 beta i hade beta 1 on it things like my images that were already on iPod would no longer be able to show up unless re taken and more noticed the new maps...