I have an iPod touch 4g iOS 5.1.1 jailbroken, and iCloud backup is not working. I click back up now, and it says estimating time remaining, then about a minute later it says 'the last backup could not be completed'. I've tried many times with the same result. The iPod was running iOS 6 but I downgraded it to 5.1.1, I'm thinking maybe the old iOS 6 backups are causing conflict. (?) Does anyone know how to make it back up?