thank you Xaria, after some tests i found a way to fixed my problem with new dance in the "Machine" :-)

Depends on which and whose "dance machine 2.1". If it is the one I am thinking of, the dances are put on a notecard and the animations are listed in the object's contents. One NC for "singles" and one for "couples". The "single" dances are put into sets, rather than individually. But, like I said, if it is the "dance machine 2.1" I am thinking of. If not then ignore all I have said ;)