Whaou, replies come quickly here, sorry about the delay of this answer... So :
@Mary : today as yesterday, I'm not in front of Mocha, but I can say I'm on Mac and I think it is Mocha Pro 4.1.2 (if it exists, anyway 4.x.2). In a few hours, I'll reproduce it and report here every tiny things which may be interesting to know;
@Terry : " I’m so happy someone else has had the same problem – I thought it was just me!" Yep hahaha, that's what I wrote above, it's always good not to feel left alone And I repeat : this is almost the only problem I have with Mocha, this is the reason why I'm happy to be involved in the potential fix of it.
@martinb : ok, thx for your reply here. But actually, I don't use tablets anyway. Read below for more explanations...
I have 2 big projects which include a lot of "insert" stuff, a kind of humor serial clips in which a young magician turns the contents of ad panels aside the road into what he feels more comfortable with So you understand that a lot of tracking must be made, and it's not a problem with Mocha.
So I track everything and export the tracking data to (most of the time) Apple Motion, because the workflow is good for I can insert a drop zone there (and then easily propose different replacement content afterwards).
When a pole happens to occur between the cam and the ad, I track it before, put this track on top, the track the ad panel and everything is ok; but of course, when passing behind the pole, the surface sometimes needs tiny adjustment modifications : this when the problem may come, because doing it well with manual keyframes affects the surface in the beginning of the clip, where everything was right with auto track...
More info after reproducing it tomorrow