At one time she was one of the world's best selling recording artists, but in recent years Whitney Houston has made more headlines for her personal life than her professional career. Her behavior has raised a number of questions and in a special one-hour exclusive airing, "Dateline NBC's" Hoda Kotb goes in search of the answers, talking to people who know her and looking back on the turbulent career and life of the singer.At one time she was one of the world's best selling recording artists, but in recent years Whitney Houston has made more headlines for her personal life than her professional career. Her behavior has raised a number of questions and in a special one-hour exclusive airing, "Dateline NBC's" Hoda Kotb goes in search of the answers, talking to people who know her and looking back on the turbulent career and life of the singer.