xsi5 : HDR +SSS problem

im lighting a scene with a hdr map. works fine for all the materials except for the SSS fast skin one im using, in which case its turning up totally black.

i put a new version of the SSS onto it and as the default it is visible but with just lots of red splotches on it.. fiddling with the back scattering scale removes this - so something is working. Just not the other parts of the shader.

anyone had anything like this before?

thanks

Try rendering the sss skin shader effects in a separate pass with lights instead of FG and then composite. With your main scene.