I've done about 20 or so home DVDs, all in NTSC. I use Ulead Movie Factory, VideoStudio, Sonic MyDVD, and usually the preivews show jittering. I went a head and burned test DVD and it played back just fine in the DVD player (not computer). I suggest you burn a test DVD and see if the playback still looks bad.
Here is a link for your references:
http://www.videohelp.com/guides.php?howtoselect=4;41