So I picked up [Colm's IDL rig](http://www.runtimedna.com/IDL-LIGHTING-RIG.html), and it has that Parabolic Reflector...

Looks great, but when I run a render, the shadow from hair strands comes out as sort of blotchy circles.

Any thoughts how to fix it?  The shadows for the spot, which is reflected back is set to:

Raytrace
Blur Radius = 5
Samples = 40
Min Bias = 0.8