I've seen a number of books, mostly children's books from scholastic, with different editions (different art, copyright, etc) that have the same ISBN number. I've since removed most duplicate books from my collection, but I had found a bunch when I last sorted my books; Maniac Magee is the only one I can remember by title. More annoying was the book with a CD attached to the front, that caused the finish to peel off when the CD was removed (the CD contained a non-working installer for a screensaver that, when extracted using other tools, also didn't work).