I don't seem to be able to add more Subjects and not always able to add check-marks to Subjects for some books and make them stick. Presently I have 23 Subjects and the only way I can add a new topic is to change one of the subjects. Also, it seems that when I do change an old subject to a new one and I uncheck it, the Subject is changed but stays checked on the, now, inappropriate new Subject though I attempted to save the changes.