I discovered, when I was busy doing something else, that sometimes the Poser 5 rendering hasn't really stopped but is taking an infinitely slow time to render. Lots of lights with shadow maps are, I agree, another slow down...the combination takes patience (I believe someone suggested turning off the shadows for all but one light but that, of course, is what I forget to do each and every time). But the results, sometimes, are so nice that it's almost worth the wait. :)