Faveral, do you have smooth polyglons on? I get that sometimes when I have it on in P5 on some models. You may want to turn it off on areas where you get the brown stuff. (you can turn it off individually on a bit in the parameter dials for that area) Also, try using a very small (0.001) setting on displacement. That sometimes helps. Hope this is of any use to you. If it doesn't work, try stopping over to runtimedna.com and posting it in their P5 section. There are some of the most excellent users in that forum, I'm sure someone will be able to help if you don't get any joy here :)

Silke