There is a nother option. with MJ poly tools what might be couseing you the problem afer a while is the history. MJ add's a lot of extra nodes also. They can have there uses but unfortunetly the delete history doesn't work to well with MJ used on a object. The salution would be to eather try deleteing history after the project has bean saved and reopend.. A or B you can have a little script like I have that exports the mesh only with out any extranse.. deletes the original and inports that mesh again. Its then perfictly clean, in and buy its self.