Curious if this has happened to anyone else. My iPhone 4 suddenly became unresponsive with no warning at all. One minute it was working fine, the next time I went to use it the screen was black and it would not turn on. In order to reactivate the phone, I had to hold to power button and the home key simultaneously for about 10 seconds until the apple logo appeared and then the phone seemed fine and has been working since. Is this a software gliche in the iOS?