I'm new to android, had an iPhone for the past 3 years, and have had my gs3 for about 2 weeks. I dropped my first one and got a replacement a few days ago. Yesterday, the "security and lock" screen started popping up randomly, and often. It's especially annoying when I'm recording a video because it interrupts it. I uninstalled every app that I didn't have on the other phone, I have force quit it, cleared the memory, removed the battery, etc. Am I missing something obvious?