DVD Menu

Premiere Elements 15, Windows 10.

My problem is that the Menu is distorted, stretched.

My videos are completed & rendered in Prem. El.15, they consist of pan & zoom widescreen & 4x3 images & video pieces, and it plays widescreen on my widescreen computer.  When I want to make a DVD, I load each one (12 videos, 45 minutes) onto a new Prem. El. project and then I notice that the setting (Edit, Project Settings) automatically changes to 1280x720 (from 1920x1080).  At the top in the settings it says Sony XD CAM EX 720p.  30 Frames/second.  Square Pixels (1.0).      

Now the DVD Menu & all templates show like a 4x3.  But when I put in a 4x3 picture (in the Pan & Zoom menu template) it shows condensed (skinny) with black bars on the sides and doesn't fill the 4x3 outline.  When I put in a widescreen picture, it stretches it too wide, and the fonts too.

I've tried to see if it would help to change the Project setting to 1920 x1080, but I can't.

Does anyone know how I can have a non-stretched widescreen menu?  (Or if that doesn't work, a non-condensed 4x3 menu?)

I've burned the DVD anyway, with the stretched menu, and on my regular DVD player it played just like on the computer: the videos were OK, but the menu was stretched.

Thank you!

Elisabeth