There's just a few different hair that this happens with, and with the exception of Shee Kiira, it's allways twisted hairstyles with curls and such. It seems as though the black areas are on the opposite side of the main surface (if that makes sense) thus why it mainly just shows up on twisted or curly hair. As far as i know it's allways done it... and it's not that it only happens on some of the mats... It's just that you can't tell it's showing up on black or really dark brown for example and different lights/scenes make no difference. Since i normally make more gothic type scenes my characters usually have black hair so it's just not usually a problem. It's also not my poser install because just to check i made a fresh poser install on my other harddrive and installed those hair styles just to check... if anything it might be a video card issue.

Anyways, using the tip Anniebel posted works fine so it's not that much extra work. I appreciate the response though.