I have an iPhone 3gs and ever since Oct 2nd, my work email that uses Microsoft Exchange keeps crashing and shutting down. I am always using the latest update and at that time it was 3.1. I am now using 3.1.2 and it still crashes. If I turn off that particular mail account, my personal email accounts work just fine. Also battery life since 3.1.2 is HORRIBLE. I go from 100% to 24% in a couple of hours.