Emily, Sometimes the way things work just doesn't seem to make consistent sense. I ran into this problem when I purchased a second notebook with P3-1000mhz, 20 gig hd, 640meg ram. Poser would not allow large renders. But it worked just fine on the other notebook which was P3-600mhz, 20 gig, 192 meg ram. I found the "swap file" fix at Curious Labs' site. I have had people tell me that this fix is nonsense. But by reducing or enlarging the swap file I can consistently make the problem come and go so I don't really care whether it's nonsense or not. (Placebo effect for computers?) I typically have about 7-9 gigs hard disk free and a 958 meg swap file. Anyhow, you have nothing to lose by trying this and it will only take a minute to change. The Curious Lab article, with full instructions) can be viewed at http://www.curiouslabs.com/support/html/techSupportFAQ.html See question 4.