The problem may be that you’re trying to render a non-standard DVD. DVDs don’t support HD, so when you go to playback in that projector it’s hard to say what it might do.
Really, to do it right, you need to film in HDV, edit in HDV, but then render to a DVD template that you’ve manually changed the output from 4:3 to 16:9. This will result in a standard widescreen DVD that the projector should playback normally.