PDF ebook pages appearing blank in ADE 2.0.67275

I'm creating a PDF ebook from a book's original print PDFs and testing it in ADE. In the old ADE version, it works okay, aside from the drop shadow/grey boxes problem that I can't seem to get rid of. In the new ADE, v 2.0.67275, the drop shadow problem disappears, but all the left hand pages in the book appear blank.

Does anyone know why this is happening?

Thanks,

Silma