This would seem to be the 24fps/30fps thing again...?
An MPEG2 from VHS source (NTSC) will always be 30fps.
So if your AVI is 96000 frames @ 24fps, but the source shows 120000 frames at 30fps, you must have used IVTC.
But it is far more likely that your source is interlaced not telecined, in which case your AVI should also be 30fps.
Try converting this video at 30fps (no 'force film') and using a de-interlace filter if interlace artifacts are present and visible.
Lotsa people asking about DVDx (all having problems).
I would recommend GordianKnot
http://prdownloads.sourceforge.net/gordianknot/GordianKnot.RipPack.0.32.beta.Setup.exe? but it won't open a *.mpg ;-(
So, WTF... try your DVDx 30fps de-interlaced, let us know if it works.
Regards