I'm not batch rendering from the command line, still don't know the syntax.. I'm on a Mac now so I'm thinking it's something like

maya -render mr [scene file] ?


I think you may be right gubar about not finding the hdri i have mapped to my sphere, but I've set the project to the correct dir and it works when I render a single image by the render button above the shelf. It's something screwy happening with batch rendering (need to render 600 frames).