Encoding Stretches image too wide

[TGM62]

I'm new at encoding and I'm trying to encode movies with DVDx 2.2 and codex 5.1. Even though DVDx defaults to an image of 648X352, the encoded image is stretched too wide and distorded. Could I be doing something wrong?

[Enchanter]

Try 640x352 or smaller horizontal resolution. It would help too if you can tell us the aspect ratio of that particular movie (16:9, 4:3 or 2.35).

Cheers.