I'm sorry if this is in the wrong place, I'm new.

I have a problem with my nook. I tend to buy a lot of my books from places other than Barnes and Noble (not all but most) so I hook my nook up to my computer to transfer books. the books are named correctly and the author is named correctly when I am getting ready to transfer them but once they are on my nook, some of them change. Either the title of the book changes to something completely wrong or the author's name changes to something completely wrong. For example, one that had me going what!? was for a book I named Matter of Time 2 by Mary Calmes, it says Matter of Time 2 but the author's name is now Bugs Bunny (yes I am completely serious). In other cases like I said the name of the book is something completely strange like that. When I hook it back up to the computer, there it is, completely correct, take it off, wrong. Is there a way to fix this? I had the first nook before this one (this one is a simple touch with glowlight by the way) and the first nook never did this. I have probably 30 books or more out of a few hundred like this and as you can imagine, it makes searching for a specific author (or book) difficult and I find that I have to actually open them up to see what they really are (if the book title itself is messed up). Does anybody else have this problem? Is there a way to fix it?

Thanks!