The screen keeps shutting off during a call. When I call someplace that has requires entering touch tones to navigate their voice system, I can't do it at all. After the screen shuts off it won't turn back on. I can't dial numbers, hangup, or anything. It's as if though it stops detecting motion. Sometimes the screen returns when I slap it only to have it shut off again after 5 seconds. There should at least be a configuration option to set the screen shutoff time during a call. Has anyone else had this problem?