Hey, guys, I'm not trying to add any oil to the fire, lol, but I just did continuous animation (only refraction changing from 0 to 300) of single golden sphere, with some bumps on it, and it shows some changes in render, expecially around specularity area, subtle, but still a change, so Bryce, it seems, calculates something different each time, also specular area is little bit bigger at refraction 300 then the one on refraction 0 ...Go figure :) P.S. Animation was viewed as BMP animation (no compression) in Jasc Animation Shop 2 and renders were BMP images...this effect is relatively small, and I'm afraid that any video compression would make it much less visible, lol !!!