I don't think the render problem is because of window size (Melanie). I always stretch the window to maximum from the lower right corner. However, I have reconstructed the scene (it wasn't saved) and have been unable to duplicate the phenomenon. It occurred at various camera angles and distances. There was a one-way wall in the scene, invisible in the Poser window, which may have played some part, though the problem didn't occur when rendering to AVI film. Thanks for the help. Next time it happens I'll save the scene and experiment thoroughly.