I have a Sprint iPhone 4S that I bought on December... One day I noticed that everytime I plugged in the headphone the phone started freezing. I went to the nearby apple store and they recommended me to reset it to factory settings. It fixed it for a while but now it seems to happen again... every time i plug in something to the headphone jack the phone freezes and it turns off. What can I do to fix this issue... Please help thank you...