Added objects in Maya missing in Unity

I have a large scene in maya, and on first import into unity, it works perfectly. Now I want to do some texturing so I go back into maya, do my texturing, and that updates automatically flawlessly.

Prob is, If i take a model that I just UVed and textured, duplicate it, then save my maya scene, the object does not show up in Unity. Im not sure what to do to make the object show up but I have tried everything I know.

Any help would be great!! Thanks everyone!

Any help? this is really bugging me

Do you mean you are duplicating the asset within Unity or using Save As from Maya or… ?