FFMpegX stretched my movies!!

[marcdcx]

I wanted to make two movies (AVI's) into files burnable on a DVD. I encoded them as Video_TS (DVD ffmpegx) and the end result was a stretched picture. Both movies were originally widescreen, and I didn't mess with any settings. Normally when I convert a widescreen AVI it preserves the aspect ratio, this was the first time I've come across this with ffmpegx software.

Any ideas why that would be? And are there any hidden settings that I can change to preserve the original asepct ratio?

Much thanks if anyone's got some insight.

[Case]

To convert a 16:9 AVI to DVD, I would suggest using the "DVD 16:9" size selector in the Video tab, as that preserves more resolution than letterboxing in a 4:3 frame.
To convert a 2.35:1 AVI to DVD, I would suggest using the "DVD 16:9" size selector in the Video tab AND the letterboxing option in the Options tab (if available) or Filters tab (when not available in the Options tab), to get the 2.35:1 picture in a 16:9 frame.