Obi-Wan said:

Luke's rescue clip: http://www.youtube.com/watch?v=nwULLrS8ZXw

@ 6:46, downfall of the Tauntaun: Is it just me or does anyone else notice that the falling Tauntaun still has this effect of a stop-motion-creature (especially the leg)? It doesn't look natural, i. e. smooth.
As far as I recall Adywan did improve the movement of the tauntaun in the first scene we see one (Luke riding it), didn't he?

The clip you linked to is still messed up. Here's a perfect version - http://www.youtube.com/watch?v=lJD6fUC7VxY

Can't say that one ever bothered me though, as I thought it was just part of the charm of the stop-motion work. I remember Ray Harryhausen saying that he deliberately 'over-exaggerated' certain movements to add 'character'. I reckon Phil Tippett did the same.