All, I have rebuilt and restored my iPhone 2 dozen times. I am on my 4th 4th generation phone. What happens is that 4 days after a restore and rebuild my battery life goes to hell. The phone gets amazingly hot and sluggish and dies in 4 hours. I have erased, restored on only one Mac. However I have deleted all firmware and freshly downloaded from Apple. Here are my questions: 1. Can having too many email accounts corrupt the iOS onboard the phone? I have 9, some IMAP, some POP and 1 Exchange. 2. Can an app do this? I think I see some emerging patters. Updating 'over the air' is generally a problem. It shouldn't be, but this seems to accellerate the issue. Syncing with Mobile me is also a potential problem source. As for apps. when Apple tuns the diagnostic software at the genious bar, only Mail seems to be crashing and is running many hidden data processes that are sucking battery life. I have tried with just 1 email and the best I get is 4 days. Is it possible for some file or account type to corrupt the system somehow? I've never had an issue with my original or 3G. Just the iPhone 4. My current build has only 11 must use apps and my 3G uses the same 'build' from backup. Side by side the brand new iPhone 4 lasts 2.5 hours in standby and the 3G all day. It is not hardware as Apple has replaced the ohine 4 times. The odds of 4 bad phones in a row are mind numbing.