I didn't see your post 15 before I posted 16.
Lots of files play okay even though they may edit with issues. And a file can play well and show as needing transcoding in Encore - and then not play well. The fact that it plays well is helpful, but does not eliminate the possibility of other issues.
An AVI file could be anything. True, the pixel size and par, the filesize in terms of duration, could be DV. The audio is odd. I just don't know.
"Jumpy" very frequently means field issues. So far we know nothing about fields. And, outside Encore, we wouldn't necessarily expect to see problems. It depends on settings at every step.