Sounds like the MT is out of scale. I had the same problem in 3d studio. MTs are extremely small in Poser. Try scaling the MT down by 100 times or so. It could also be the source obj you are trying to modify is out of scale. Translated back that would cause explosions as well. Also, AM may not be saving the vertices out in the same order. This will also cause explosions. If AM has some optimizing features like compressing vertices and such, tyurn those off.