Are you using Poser Pro (either with or without SR1)? I've noticed this same goofiness after I started using Poser Pro. Never got it at all in Poser 7 SR2.1. If you are using Poser Pro, check your Firefly render settings and see if the HDRI option is checked. I seemed to remember that problem would crop up if it was enabled, but stopping-and-starting the render over seemed to correct it.

I think the problem might have been corrected in SR1, I know I haven't encountered it since getting the SR1 update.