I accidentally upgraded my iPhone 3G to OS 3.1 from 3.0 a couple of days ago. Since then, Ive got random and complete shut downs with my iPhone and ..... it happened several times a day. Every time when it shuts down, I have to do a manual reboot with my iPhone to get it back to normal. It was fine and smooth when my iPhone OS was 3.0. Does anyone have this type of problem? I wont have the courage to do the upgrade again if Apple releases later versions, but rather stay with 3.0 if I can save my iPhone back.