why is a bit missing?

avi codec 5.10
osa 8 100%
sometimes that little black bit is there and sometimes not!


Do you mean, either its there throughout the whole animation or it isnt there at all, or do you mean it shows up on random frames?

all frames-but can change.
as i make the video i run it several times.
usually it is there throughout
other times it is not to be seen thru the whole 180 frames.

Usually these kind of errors appear when you have duplicate meshes on the same spot.

just one mesh
UH UH it was not a mesh it was a curve! that was a track
so i duped it and made it a mesh.
zapped off most of it just leaving enough to cover the problem.
it works