Well, I just downloaded the shader and built a quick CD using a pair of lofted concentric circles. Using the settings from A|W's site, I got it in the general ballpark (see attached image). I also created a pair of cylinders - one poly and one NURBS - and applied the shader. The results are what they should be and not that extreme rainbow effect that you're getting so my first guess is it has something to do with either your geometry, the camera angle, and the shader's brightness setting...or a combination perhaps.
Try this: create a NURBS circle, duplicate and scale it to create the inner hole. Then loft between the two. Now, apply your shader using the settings Rage posted, do an IPR render and start tweaking settings. If you look at the AW settings screenshot, they've connected additional nodes so don't be afraid to experiment a little bit.
Hope this helps some.
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