Armature messes up when export then import it

I wonder, did anybody have problems/solution with bvh export/import? If I export the blend file found here https://www.dropbox.com/s/20pno7txud5ae8o/untitled.blend?dl=0 as bvh and then import it back, the imported armature doesn’t look anything like the original. Could anyone please have a look and advise?