Slight Aspect Ratio Change

[Warmbeer]

Trying to reduce the size of some videos originally taken with an older Canon DV recorder in AVI format.
Not really familiar with all the details of the conversion choices so i tried all the defaults as they came with the download and got these results:
H264+MP3 = slight change in aspect ratio
VP80+Vorbis =sound only
H264+MP3 TS = slight change in aspect ratio
Dirac + MP3 TS=sound only
Theora+ Vorbis OGG=video only
MPEG2+MPGA TS = crashed on 1st try - then slight change in aspect ratio
WMVA+WMA ASF=sound ok - video = just blotches of colors
DIV3+MP3 ASF = conversion completes but will not play in VLC

Seems like the 2 H.264 versions are the most viable for whatever reason, but the aspect ratio change is disturbing. When i look at the info on the original file it shows:
Resolution: 736x480
Display Resolution: 720x480
While the converted file shows
Resolution: 720x480
Display Resolution: 720x480
It seems pretty clear that is the problem.
Is there a way to adjust for it?
TIA