[lscime]

I only know SolidWorks, but I assume that AutoDesk isn't too different. When your teammate puts the parts in the assembly does he mate them or constrain them (I'm not sure what the AutoDesk word would be) together, or is he just "putting them next to each other." e.g. does he click a face of one part say "be coincident" with the face of another part (or something similar)? If he is not doing this then that could explain the problem; parts need to be constrained in assemblies.

I hope that helps,

-Luke