I'm coming in on this conversation a little late, but I have the same hair rendering problem with white whispy ends when I used the Sapphire Fox hair.  I dropped by to see if anyone knew why this happens as it's my favorite Poser hair.  I assumed that it was bad hair texture transparency.  I even purchased another texture package for the hair, but the results are the same. 

Any suggestions on a hair texture package for the Sapphire Fox hair? 

I will try to change the texture filtering and see if that helps.  I don't believe it does,
however, as I think I've tried that before.

Thanks,

Bobette Bryan