My phone occasionally has black, vertical streaks on it. It almost looks like the screen doesn't fully shut off. When the phone is off, normally, the screen will be grayish in color. When the phone is on the screen background will be black, but sometimes when my phone is put on standby the screen will look like a combination of both. Does anyone else have problems like this? Is it normal? I can't reproduce it when I want to. It's just a random thing that happens every now and then. I've only had my phone for about 5 days now.