It seems that there's a neverending bugs found on the new ios6.1.1... this time it involves specifically again with the iphone 4S....though it might not be widespread as I thought it would be.. but for those Istoryans that are not yet aware of (especially those who have an Ip4s, it might be noteworthy to see this link and read it first) before you take the plunge of updating your old ios firmware..
iPhone 4S Battery Headaches Persist for iOS 6.1.1 Users | Gadget Lab | Wired.com
I'm sure Apple is currently on the works already for a possible software updates to remedy it..