Actually, at least one bug has been reported by several people - polygons not rendering properly in firefly draft mode. There's several posts about this. I included an example in one post and have some pictures on my web site showing different rendering types on different pictures, a few showing missing pieces. My specs: XP Pro, 512MB of RAM, 1.7Ghtz CPU, over 2GB swap space available. Installed P5 over P4.