Thanks,
update: using Flash CS3
export as quicktime-movie checking “After time elapsed” setting; insert data as hh:mm:ss.ms that one gets from number_of_frames/framerate, rather than leaving the default option “When last frame is reached”.
In this case there’s no need to copy frames belonging to nested timelines to the main timeline; better is not to have a “Stop()” action inside the very last frame.