If you mark a book as read then switch the "current edition", and THEN add the book to the "Owned" list within the book button, it will add the cover edition, not your current one. This makes little sense IMO; I hardly understand the effect of "choosing an edition" if it's not going to let me interact with the book, from that point on, in reference to that edition (see also the "Choose editions for stats, lists and prompts" feature request)