Can't backup my mannually added epub books
In iBooks, I have several books and PDF files. When synchronizing with iTunes, books from the bookstore and PDFs are saved and transferred into iTunes. But I cannot do the same for manually added ePub books that I added using USB transfer (I think I used Downloader lite). Anyway, since I am using generally Ubuntu, I use the iTunes sharing folder from an app to copy stuff in my iPad from Ubuntu. Then I just open the app, select the file and do a "Open in..." to put the file in the proper native app.
I have three books that I got a long time ago, put them on my iPad using Ubuntu. My problem is that I cannot find the originals on my computer, and I would like to copy those 3 books in my iPhone. If only I could find my cd from where I rediscovered this books, that would solve my issue...
But I find it strange that manually added PDFs are saved, but not manually added ePub books...