This won't be of any help I'm sure but here's my 2 cents.

None of my older furred creatures have stopped working with sr3  On the contrary, they all work better and dynamic hair is stable now. In my opinion this is not a Poser issue but rather how the hair is set up (as have been said earlier).

One thing I noticed with the Lycanthropos fur,  when I had the chance to look at it,  was the hair groups density was set much higher than I usually have on mine. Where I have 10.000 for density the Lyco' could have 200.000. I don't know if this happend with sr3 or not but it would have an impact on the render. Especially if one is using shadows and raytrace. Also the amount of strand vertices make a difference.