One thing that seems to have been fixed in this beta, although it hasn't been clearly identified as fix except under the 'general render speed improvement', was the render speed slowdown that would sometimes cause a simple scene to takes hours to render depending on the camera position. I was trying to compile a definitve bug report for this, but, having just tried my example scenes with SR2-Beta2, the bug seems to have been solved. This is a big relief since myself and, I suspect a lot of other people, were finding this bug alone made working with P5 impossible. Bill