Previously we confirmed that A4 devices on iOS 5.1.1 firmware can be jailbroken — that doesn't mean you need to update to iOS 5.1.1
Actually, all users having an A5 / A5X device should stay away from iOS 5.1.1. The popular Dev Team member — MuscleNerd posted a warning via Twitter, informing jailbreakers having an iPad 2 / 3 or an iPhone 4S to stay away from the iOS 5.1.1.
|MuscleNerd Warning Status|
Keep in mind that iOS 5.1.1 jailbreak is still tethered!