I just took a quick look, but it seems that disabling 'double sided' in the object's attributes under 'render stats' did the trick. FYI it renders both sides in maya software by default until 'double sided' is disabled as well.
Oh, I think you can do it on Render Layer properties. Just select the defaultRenderLayer, go to the attribute editor, and set "Double Sided" to "Override On". Should do the trick.