With my previous iPhone 4 running iOS 5, iCloud backup would occur when the phone was locked, charging and connected to WiFi. However, the backup would occur only once every 24 hours, regardless of the amount of times the above conditions were met. On my new iPhone 5, running iOS 6, iCloud backup seems to occur EVERY time the phone is locked, charging and connected to WiFi, regardless of wether backup has occurred in the last 24 hours or not. Has anyone else noticed this? I'm guessing this changed with iOS 6.