Unable to Xfer e-book, from ADE, to a tablet device

Have ADE V4.0 running on a laptop under Vista. Have authorized with an Adobe I.D. Can download & read e-books fine BUT when I try to transfer/copy an e-book to my Nook I receive an error msg: "<tltle> CE_Copy_Not_Allowed - No poermission to copy this book". This happens using both "drag & drop" as well as the "copy to my Computer/device" button. The device shown is the Nook. Any suggestions??????????

Is this another de-auth/re-auth issue?? have done this once with no change in ?results?!