Exported video animated graphics looks choppy

That's pretty much normal behavior. Your graphics don't lend themselves particular well to MPEG compression due to the many solid color areas and that causes this "block pumping" at the beginning or at hard cuts because the MPEG stream needs to adapt. I would suggest You use CBR encoding to minimize the problem, but it will never completely go away unless you change the design to be more MP4 friendly with more motion and finer details.

Mylenium