When I'm doing a three way call, I call my first contact with no problems. However, when I start to dial the third person, the screen blacks out. I hit the button on top and the screen lights back up. I hit a number and suddenly the screen blacks out again. It takes several attempts like this to dial a number. Is there some setting that will stop this, or is my phone headed for trouble? Do I need to take it in for work, or is there a solution? I've only had the phone about 3 weeks.