Hi,
I often look at this forum, and it's my first contribution.
With Carrara 6.2, I spent hours to track an object whith the hand of a character on my stage.
When I activated the track behavior, my object disapeared.
I found the solution:
The name of the target track MUST BE UNIQUE...
The bone's name "hand" was shared with other characters not visible at this moment and the object jumped out the screen.
With the name "hand-A", it works fine.
Hope it will help other Carrara users and that DAZ correct this bug.
Have a nice day