Can't copy my book to my e-reader

I am trying to drag my e-book to my e-reader withing Adobe Digital Additions.  the book is sitting there but when I drag it to my e-reader the following message comes up - CE_COPY_NOT_ALLOWED - No permission to copy the book.  I paid for the book and it came up on Adobe but i can't drag it to my e-reader.  AAAARRRGGGGG