iPhone 5, iOS 6. Recently switched from a 4-digit passcode to an alphanumeric one. Twice recently I've been in a situation where it wouldn't accept my passcode. And it won't permit an emergency call. Reboot is the only remedy I've found. This is quite literally a potentially lethal problem. Take a look: http://youtu.be/zFeX_uPNzL8 I've opened a case with Apple and will update this thread if anything comes of it. Meanwhile, anyone else heard of such an issue?