I'm having some issues getting the difference matte to work in a 16:9 project. No matter what resolution I try for the reference frame image, it never sees it as the right size. For instance, if I just export the reference frame as 720x480 widescreen, the matte sees it as 4:3. For other resolutions, it appears at other strange proportions.

I've run out of ideas. I've tried a bunch of different resolutions and proportions, and none work like they should. It's like the reference image needs its 'Interpret Footage' set, but that can't be done. Has anyone ran into this problem before?