I am building a widescreen DVD and have a question. I am creating my menu background images in Photoshop and using DVD Architect Studio 4.5 to author the DVD. If I start with a 720x480 image in Photoshop, the image is distorted (stretched) horizontally if I have the 'stretch to fit' setting selected for the background image. If I have the 'letterbox' setting selected, there are black bars to the right and left of the image. So my question is, what resolution should I start with in Photoshop to prevent the image from being distorted or letterboxed?

Thanks.