Hello. I have a problem concerning ebooks and ebook readers on my device. I have added a number of epubs and pdfs via the iTunes software to my ipad, and i have downloaded from the store a couple of ebook readers, namely xodo pdf and acrobat digital edition . However even though the native reader- ibooks- can find the books just fine, the other readers cannot find them. Anyone else had that problem??? iBooks is a fine app, but i 'd like to have more options!!!