Boni, it turned out the texture was missing from the soft tissue, that for whatever reason it wasn't automatically applied. (I didn't even know what part of the body "soft tissue" referred to, so I'd been ignoring it. I figured it out by turning the diffuse color to green.) I'm not familiar enough with the material room to know which nodes are "extra"; I deleted everything except the basic diffuse and they turned black. :( I usually render in Reality, it's easier and it looks better, but I'm having the same problems there, so I'm not sure it's a material room issue, but here are the node settings for the sclera.