Issue not resolved, I thought I had found the answer. IC certainly effects it, but in continued testing I found that I was getting this pattern where the dark areas occur

The pattern was a black point surrounded by a lighter circle and they appeared in a grid like fashion. So I'm thinkin if it's in a grid or a somewhat regular pattern it must have something to do with the mesh. I sculpted this in Zbrush so I'm using displacement maps to retain the greater details. When I turn off displacement maps, it completely go's away.

And the black marks don't appear untill the SSS pass. So it seems to be an issue when SSS, IDL and displacement maps are used together. I did not mention displacement maps earlier because it just hadnt occured to me that they played any role in this. I wondered if displacement bounds settings might correct this. I started out at .3 went to 1.0 and aborted because it was taking forever. Tried a render at .60 DB's stilled slowed render and marks were still there.