Same problem here. Charge 100%, phone off for 9 hours, 90% gone. Used TasKiller before shutting phone off: charged 100%, off for 9 hours, 30% gone. Used TasKiller and left phone on, 100% charge on over 9 hours in sleep mode, 100% left. Can't understand how leaving apps on and phone off can drain a battery more. Seems to be fine if I leave the phone on.