Yes I have trouble, my pc is authorised with ADE the books bought from Waterstones appear in a bookshelf, alson on the Elonex 511, but, then a annoying box pops up saying no valid lisence for this book, useless do not buy. Have been in touch with Waterstones, Adobe, and Elonex they all do not want to know, the just send you round in a never ending circle of excuses, the ebook is on sale somebody should take responsibilty for product, I am going to my local Waterstones this morning, somebody is going to have is day spoilt. Jeff