Something odd with my 7 Plus has been going on. I'll be in the middle of doing something on the phone, it will sort of freeze and then the screen goes black as if I powered off the phone, then all of a sudden the screen to enter my password appears. Also, certain videos that I stream from the web don't appear on my screen and I only hear the audio. Sometimes it takes several tries before the video actually plays along with the audio. Anyone else experience either of these?