yes, it's true - it's necessary to drop shadow bias to 0.1.  below that and I get small artifacts on the skin and shadows using IDL with the unmodified vss settings.  however, bill said to use his P8SSL.pz3 for IDL, as it's got an adjusted vss control prop to prevent toe-crack self-lighting, which is an admittedly unnoticeable detail, given the improvement of the skin using vss when compared to the old-style poser render.  basically nobody's gonna zoom in like this, but I was trying to measure the ground plane and I spotted it.