No idea what I did wrong, but I imported an figure OBJ mesh, went to the Setup room, imported a skeleton (P7Ben), adjusted the skeleton for fitting and did the autogroup as a start. Works wel, but when I go back to Pose, all the arm parts are rotated (not the T-pose). So the orientation of the skeleton is not the same in Pose and Setup. Legs are fine, but maybe it is because the changes are minimal. My OBJ mesh has no T-pose, so I have to adjust the Ben skeleton. 

You're better off building your own skeleton bone by bone.