Are you using EPUB format? I think Aldiko only supports EPUB, for imports. I just did this yesterday, after having some issues (something dumb I did). Worst case, refresh by wiping the /Adiko folder on the SD card, the Ebooks folder on the internal memory, wiping all stale books on your shelf, adding the EPUB's back to /sdcard/ebooks/import and re-trying the import.Their import process is the only negative I have about the app. It shouldn't be this complicated.