@cr1 and @trent
I took a look at Figur 3-20.skp and noted that there is some type of corruption in the file.
I noted that some faces do not receive a Texture or Light correctly.
Within the OP file; I then made a new simple cube, grouped, made a solid group with all faces oriented correctly and made the texture “default”. I noted some differences in default face shades. I next added texture Chris_Skin (from OP file) to cube.
I then noted that of the six cube faces: (1) three faces were not the right texture shade (the other two on the backsides), (2) as you rotate the cube (with shadows off) the face shades also do not get lighter/darker based upon orientation.
My observations do not reveal the geometry error or corruption, but clearly as LayOut reads the file it encounters some problems too. Hope this might help someone track down the problem and add some insight to the issue.