Depth Map issues via the command line for Maya 2012 Linux

I’m using Maya Software Renderer at the Command-Line (Maya 2012 Linux) and it’s producing an extra file (*_depth.[file format]) for each frame rendered. I have tried the -depth flag to turn Depth output on or off with no results. I have also double checked to make sure the check box on the render globals and camera settings for depth are unchecked.

Bottom line is I don’t want to output the depth map. It takes too long to render and the time adds up quick. Any help would be greatly appreciated.

Thanks in advance!