I have the Samsung HT-X50 Home Theater system. I connect it to my TV using a HDMI cable. My TV is a capable of a 720p resolution. But my home theater when connected says 420p. Why is not able to display at 720p. And I am not talking about when a movie is being played. Even when its idle (both tv and home theater are ON) it displays 420p. Can someone tell me if I need to change some settings?? Thank you.