Originally Posted by shalym
That's a different case. The publisher decides whether or not to put DRM on the book when the book is uploaded If a publisher decides to put DRM on a book initially, I believe the only way to change that (remove the DRM) is to re-publish the book.
The decision was made to NOT put DRM on the book when it was released
(i.e. uploaded), but I suppose because previous books from the same publisher were infested with DRM, Amazon mistakenly added it anyway.