The Divx codec did the trick. So now I've opened my script in vdub and tried looking for the frames like omegamattman said but I don't really know what to look for or how to count them.
here's about 100 frames uncompressed from vdub after running the separate fields script if any of you has the free time and inclination to look at it and see if you can help me figure out what frames need to go (57mb)
http://www.mediafire.com/?6i85yub38uzyram
This is a complicated hobby! :)