I have a necromancer spellbook, which shows as having 16 spells in it when moused over. When you double click on it, and open it up, it shows that it is missing the Exorcism spell. Now, when I try to put an exorcism spell INTO the book, it says "That spell is already present in that spellbook." Um, no it's not. Is the book bugged? Is this a "feature"? Am I missing something?