About two days ago I upgraded my 2G iPhone to latest 3.0 Firmwire sucessfully, but in last two days I noticed that with 8 hours of battery charge, my battery lasts for only about 3-4 hours and that's without really using it. Yesterday and today around 1PM my battery died when I was at work. And also it gets too hot. I don't know what's going on, does anyone have any idea? Thank you.