Wow, your image does have a lot of artifacts, and yes, IDL does cause them.  I just might revert back to IBL, just thinking about it.  Tried another hair and it's got quite a few artifacts, and I have Irradiance catch at 50 & Indirect light quality at 32, I believe that's a high quality setting as far as IDL.

No, I don't have PP12, I only have Poser9, and Morphing Clothes did wonders for me.  Here's an image using Morphing Clothes on quite a few clothes for young girls and a teacher (classroom) I did long time ago in Poser.