I would say:

 - increase bounces, as nature itself applies an infinite number of them, and the setting is just a cut-off speeding up render time somewhat at the cost of creating artifacts. Poser applies the amount of bounces it needs, adhering to an upper limit as set. By applying the Render FireFly option from the Scripts menu, you can adjust the IDL bounces separately.

 - reduce the lighting levels, as the splotches are apparent cases of overlit areas. Poser handles the lighting internally the correct way (as it uses EXR format) but when presenting the result, levels are clipped.

 - gradually increase quality settings, as higher levels come with longer rendertimes. You have to find yourself some best balances for your drafts and finals, for this scene.

Hope this helps

- - - - - 

Usually I'm wrong. But to be effective and efficient, I don't need to be correct or accurate.

visit www.aRtBeeWeb.nl (works) or Missing Manuals (tutorials & reviews) - both need an update though