Auto-lock doesn't work after updating iOS 6.
I'm using iphone 4s. After updating iOS 6, the auto-lock function doesn't work anymore. I left it for 10 minutes and when i came back, the screen was still on although the auto-lock time is 2 minutes. I tested many times, tried to reboot but it didnt help. But the screen auto-lock is still working. Does anyone have problem like me and know how to fix it ?
iPhone 4S, iOS 6