There was an apparent bug that was never declared in Firefly that seemed to increase rendering times by a factor of 50 or more, even in simple scenes without raytracing or shadows. This may well be what you have encountered. I saw it with single sided squares at some specific camrea angles, but never experimented with hairs. This was apparently solved in SR2-Beta-2, even though it was lamely described in the read-me only as 'render speed enhancements'. Bill