Encore letterboxes widescreen footage

[koberulz]

I've got a widescreen mp4 file, with square pixels, which displays fine in Encore initially. Once I transcode, though, Encore adds black bars top and bottom, squashing the picture. If I go to 'interpret footage' and set it to 16:9, the timeline it's in changes to 4:3, which allows the black bars to remain while showing the picture properly.

How do I stop Encore letterboxing the footage?

[guns1inger]

Post a mediainfo of the original file.

Personally, I hate using authoring tools for encoding. I prefer to encode with a good encoder (HCEnc), then bring that into the authoring tool for menus/subs etc.