Anyone using smart stay notice it hanging and keeping the screen on long after you've stopped using it? It has done it twice today, that I've noticed at least. The first time I didn't time how long it stayed on before I pressed the power button, but this last time I let it stay on for about 5 minutes before messing with it. After I press the power button first to lock the device and a second time to turn the screen back on it resumes proper function.