I have an ipod 4g Jailbroken on ios 5, and my memory seams to lower as i go through the day, if i leave my ipod running over night almost ALL the memory would be gone, and i wont even be able to unlock my device, but whenever i reboot my ipod i get all my memory back, but as i said before it continues decreasing, whats the problem? You think its startup daemons?