It's a model error maybe. Are you sure you have all the playerCharacter fancy joints/specifically named meshes and what-not?
One thing to remember is to have the Collision Mesh and Bounds and all that other stuff in the .dsq files AS WELL as in the sourced .dts file, otherwise the engine will not know what the forget.
So make sure your .dts file for the turret includes the collision mesh (named something, I dunno, look it up somewhere) and the bounds mesh (if not automatically generated on export already). Then make sure the root.dsq file for your model also contains all that stuff and the same joints, and do the same for your look.dsq (look was it? I dunno)
You will probably get further problems if using MS3D, like box shadows and "submerged model syndrome". I can't help you with those.