Solve the draining battery problem
I'm running 4.3.3 on the iPhone 3gs. The battery started to drain very quickly and heat up the iPhone after 4.3.2. (It was after the version which allows apps to run in the background.) Turning off the location services and shutting down the background apps (double tap on the bottom button to see which ones are running) helped but did not solve the problem. What solved the problem is re-setting up the iPhone as a new phone. The OS and apps were re-installed from scratch, and I lost all the photos, videos, music etc. from the iPhone and its backup, but they are still there in iTunes. Now I can add the music, video and photos back that I *really* need. I charged the battery and after 24 hours it was at 74%. Previously it would drain completely in a few hours. And the iPhone no longer heats up. It is really difficult to find this information on the web.