Originally Posted by taming
I have downloaded other ePUB books using ADE from other stores and although they appeared in the "My Digital Editions" folder on my desktop, they never somehow landed in on my bookshelf within ADE so I could not drag them onto my Kobo from there. My solution has been to side load them through Calibre.
Try to import them into your library (although they're already at the directory and it looks redundant). It should work. I think that the reason is the books you're talking about don't have DRM, so ADE only opens them, it doesn't add them (how it does through acsm link).