I run in to this all the time. my workaround is to export “using quicktime movie” (not using quicktime conversion)to an uncompressed 8-bit file. I take a hit on the large file but it is one of the few codecs that renders a file without the field artifacts. After the export, you can compress your file to Mpeg2 with your favorite transcoding App. This may not be the best or the most efficiant method but it works for me.
Kris
G4 dual 1.0
1.25 GB SDRAM