It appears that you have made a difference (a larger sphere minus a smaller sphere), made copies of the CSG object, then unioned one set and merged another another set. I made this object in the first image by doing a merge of the two smaller spheres and a merge of the two larger spheres. Then I did a difference of the two CSG objects and a box (cube).

The object in the second image was much simpler to create. I made two spheres with the hollow function activated. I created a CSG merge object of the two spheres. Next, I created a CSG difference object of the previous CSG object & the box (cube). Note that the box's texture was made with a simple single color pigment with 100% transparency.

David wrote:

Hi All, I seem to be having some trouble with CSG merges in Moray for Windows. Attached is a image that I basically copied out of "Raytracing Worlds with Pov-Ray 2.2" book. As I understand it, the "Merge" image should be completely hollow. I made this image as a test after other merges I attempted seem to fail, Is this a bug in Moray or am I something important? BTW, Sorry if posting binaries here is wrong. But, I figure this is the best place since I use Moray and haven't figure out Pov_ray script yet. Thanks,David