the battery in my iphone3gs has been suffering pretty bad lately. it drops about 1% every 5 minutes while using it. I turned off the phone, 3g and data and killed all the processes in sbsettings and it still drains that rapidly. It IS connected to wifi all the time but it didnt use to drain that fast. I don't have any moving themes or backgrounds and my backlight is set to 50%. any theories?