The default depth map lighting is really pretty much useless if you are looking to render realistically.  Delete them all using the built in python script and recreate your own with raytracing shadows.  The renders do take longer, but you will get better results with SSS and reflections.  Also, PP2012 has gamma correction built in and is active as a default in the render settings.  This means you will require lesslight intensities in your scenes and less lights if you use a self illuminating skydome for outdoor environments.