You should set it to render in "separate process", if you haven't already. That will force poor little archaic 32 bit Poser 8 to create a Firefly render process independent of the Poser.exe process, and free up some system RAM for it to use. Or so goes the theory. Even so, a scene that large would be a problem for any 32 bit app, and if you already have separate process ticked off, no idea what else it could be.