Just a hunch: I would imagine that Poser is trying to use some temp space or a .tmp file somewhere for the render that is space restricted by the Operating System. (In XP I think its something like: c:documents and settings{username}temp or c:documents and settings{username}Application Datatemp. I do not have my dual-boot up in XP to verify the correct path. I know I used to get these types of errors when trying to install some software with these temp directories "filled". Perhaps this may be the cause?