Am I missing sth. important that I can not see right now?
Here is what I would like to achieve … The normal pipeline I think? Correct me if I’am wrong - But the aim is to map my maya character with MoCap data from this device here (Fullbodytracker - http://nodna.com/FullBodyTracker.27.0.html) … First Step we have done: recording some testanimations in the original FBT fileformat - then converted this to a fbx file … opened that fbx file in MB it gives us markers who correctly represent the motions we recorded. Ok - no problems so far. Now I created the actor in MB and try to reshape him so that he fits our markers … Still no probs here, but then there will be sth. I cant’ figure out … I have surley researched how to do this the correct way in the autodesk area and in the web but I seem to miss sth.! So what have I done - I created the marker set for the actor and alt-dragged the right markers in there. I oriented all of them and then I let MB snap an recalculate the translation and rotation. And MB should activate the mapping onto the actor, right? So that the actor would be driven by the mocap data markers … But MB doesn’t … He moves the actor in a strange pose … but when I hit play - nothing happend??? Do I miss a step … or what … ??? In the theorie that actor then should drive my characterized character but I cant’ test that right now, because the actor stays unanimated!
Thnx for every answer helping a mocap “newbie” … 
just too “stupid” to ask for/to easy to answer!?