Hi, I am using the Ipod touch 3rd gen, upgraded to IOS4 (the version before the most current update). I tried the ibooks app for the first time and am very disappointed in how quickly the battery drains out. Reading for an hour continuously drains the battery from full to about 20%. The screen was on 75% brightness. Is that normal behaviour? My ipod is 6 months old, moderate to heavy usage daily.