I recently got the iPhone 4s for my daughter and are having trouble getting the screen to respond after being idle for 10 mins or so in screen lock. We have to try a number of different things in order to get it to start responding. Once it responds the slide to unlock bar works and it function s normally. But every time it sits for 10 mins or so after being locked it gets stuck again. Anyone have this issue or know of a fix? I turned off the auto lock feature to cut down on the number of times it happens but not a solution.