Quote - I have encountered this as well in Poser 8.  It seems to occur more often when I am using IDL than not.

No rhyme nor reason to it that I can find, just sometimes it only renders what is visible in the window at the time sometimes it grinds its way through the whole image.

Also, it appears to happen more frequently if I start the render through the RenderFirefly script rather than just clicking the render button. 

 

Yes, that's the frustrating thing, that there doesn't seem to be anything in particular I've noticed that causes it.  I'll try the render button more, too, along with that render in background.