I have 2 Poser jobs (.pz3) which I have revived; I started them in November 2011. I now have Poser 11. In them, the backgound has large areas of nearly flat ground, and I get Poser objects and people to cast shadows on them by placing a one-sided square on the background's ground surface and setting its material to "shadow catch only" mode, and running in Firefly. (In November 2011 it ran OK.)

In one job, running in Ray Trace shadows and in Depth map shadows (as selected on the dominant light's properties panel), renders OK, and shadows of legs render sharply as expected.

In the other job, rendering in Ray Trace mode produces no "shadow catch" shadows, and rendering in Depth map mode produces "shadow catch" shadows only for large bulks and not for legs and similar, whatever I try.