One of the reasons I bought an iphone was for it's purported stability. I am a fairly light user, meaning I can get through 2 or 3 days of use per battery charge. I don't use the phone continually all day long like a lot of people. Nonetheless, I encounter random crashes, at least once a day. This includes apps just stopping out of the blue. On another occasion, the entire screen just magnified into a giant pixelated image, and was unresponsive. On other occasions, the screen just froze. I am on ios 6.1.2. Is this pattern of glitches 'normal' or should I be concerned enough to bring it into an apple store (I really hope I don't have to do this).