Some time ago several European carriers including Vodafone told their subscribers not to upgrade to iOS 6.1 due to connectivity issues experience with the new iOS version. Users who installed the update found that they couldn’t connect to the Internet, make or receive phone calls, or send and receive text messages. Apple attempted to rectify these issues with the release of iOS 6.1.1, but it looks like the solution came with its own set of problems.
Apple iPhone 4S users who upgraded to iOS 6.1.1 have taken to the Apple Support Communities complaining about battery life and heating issues after the update. The iPhone 4S generally offers around 7 hours of battery life, while post update users have complained that their battery life was down to 5 hours or even 4 hours after updating.Fortunately the connectivity issues don’t seem to be an issue anymore.
Another issue discovered on iOS 6.1 was the inability to connect to Microsoft’s Exchange services for syncing and another issue which allowed anyone to bypass the passcode lock mechanism on any iPhone running the iOS 6.1 update. Hopefully Apple has already started working on these issues, but they will now have to add this new battery draining issues to their to-do list before releasing their next software update.
source – Apple | CNet | Wired