Glo Library on memory card doesn't show up at startup

A few days ago I've put all my ebooks on a 16GB uSD card, leaving none of them on the Kobo internal memory.

The result is that when I turn on the Glo no book shows up, so I have to go on Library -> Books and then the list comes up.

What can I do to avoid repeating this operation each time I turn the ereader on?

Thanks!