I am trying to edit my old family videos.
My aim is to produce updated and compact videos, playable on the Media PC and modern display devices (LCD, Plasma, etc).
When I play the rendered videos they show in the wrong aspect ratio.

The source videos were captured to AVI files as NTSC DV - interlaced, 720x480 pixels, 0.9091 PAR, and 3x4 display aspect ratio.
I am rendering the edited videos to MP4 files as AVC H264 - progressive, 720x480 pixels, 0.9091 PAR.

To play the videos I use MS Media Player, GOM Player, KMPlayer, and more - all show the wrong aspect ratio - 3:2 instead of 4:3.

I use the 'Vegas Movie Studio HD 10' to edit and render videos.
I have tested a great deal of combinations of project settings, stream properties and render settings. But the videos are still rendered as 3:2.
I also checked out Vegas for SAR settings, but found none.

After a week of consultation and research I am still baffled-
Is there no support for non-square pixel ratio with H264 or MP4?
Does the problem lie in the latest Vegas Movie Studio I am evaluating?
Is this a gimmick to push me to buy the Pro version?
Or maybe I still did not get the right configuration/setting for rendering such a video?

If you know of the correct settings to render the videos properly then please elaborate.
BUT - I wish to avoid resizing the video frame itself. I much prefer setting the SAR/PAR/DAR properties.