Everything went smooth, a great 3d track using the AE6 track from adobe. My element looks great , but if update this element to something else, the track get lost. Besides if I add any other element, this will happen again.
Nope, Ive change Element objects with no problem. But you must remember if your object is sitting on the ground, you must remember on the the new object to set the achor point also at the bottom in Elelemt. Andrew shows how to do this in one of his videos.
As you said, something for me goes missing along the way. Once I start to change the position of the elements in the world transformation, they go wrong. As you said could be due to the anchor point. I am not sure what makes the tracking fails. If I am careful checking the right things and change them , everything goes well.