I get this problem when using SSS and then using the V4 Skin Realism Kit. That Skin Realism Kit is great but it does not work with SSS; it was made before SSS existed.

Sometimes, python scripts alter node/material settings without taking SSS into account. That might be the problem. I'm still searching the forums at runtimedna; I know I saw someone else with this problem and Poser Pro 2012.