Attached Link: http://www.stewreo.de/poser/firefaq.html#8

*From P5: reversed normals are a major pain. The "normals forward" option of P6 fixes the problem - more or less. Models that have their normals pointing the right way are still better.* You can get around these in P5 as well by using separate diffuse and specular nodes instead of the inputs of the PoserSurface node. See the link.