DVD only plays on Mac

This is my first project. I created a DVD on Studio Pro 4.2 It works in the simulator and burned properly. The DVD plays on a Mac, but won't play on a PC or dvd player. Resolution set to 720 480i letterbox. Original is 720 30P HD.

Preferences are MPEG-2 SD factory default, except aspect ratio is 16:9. I tried burning a DVD - & +to make sure it was not the media. Any help appreciated.