I've had my phone for 4 days now, and no issues. Actually quite pleased until today. Knock on takes a couple tries, knock off works great. Tonight while phone was sleeping, wouldn't knock on at all, no matter where or how hard I tapped. Used the back button, but it shut itself off shortly after, every time. Rebooted, and same thing. WAY too early for these kinda quirks! Don't know if I'm missing something, but not happy right now!