I ordered the proof and made the needed corrections. Uploaded and revised still no option for ISBN its greyed out. My guess is because its a digest size?
Possibly. Not all books can have an ISBN and Dist, and neither can PDF e-books.
If you look here >>> http://www.lulu.com/create/books any type that has a tick on a green dot can have an ISBN and Dist.
Digest is not eligible for distribution, I believe.
At the beginning of the wizard, the sizes and bindings which are eligible for distribution are marked with little green checkmarks.