Aspect Ratio Problems with iDVD

My FCP 10.2.1 project has 16:9 video from several different sources. As usual it exported fine and previews fine in iDVD 7.1.2

After it burns it previews fine in full screen within my computer and if I play it on my PS3 it is fine as well.

My concern is I have another DVD player that “postage stamps” the video. This same player plays other commercial DVD’s fine (filling screen)

I am worried that my PS3 and other players might be automatically “Filling Screen” Id like the video itself to just fill the screen by itself without the help of an “auto-fill” feature.

Does anybody out there know what Format/ Resolution I can set my project in FCPX to give me the truest 16:9 that iDVD can use?

Also, would exporting a FCPX video as Pro Res make the video look any better on an iDVD? I recognize that iDVD isn’t Blu-Ray, but I heard it was something called “HD-DVD? Is this true? Is it worth exporting in Pro-Res?

Thank you in advance.