Ok, so I sold my Griffiths Introduction to Quantum Mechanics book on half last week. It's the book I used back when I took the class in, eh 2006 or something. The other two people in the class with me at the time had the same book (green hard-cover, cloth-bound book with a blue glossy cover thing on it with the title and picture of a cat not in a box, hah). When I listed the book, I grabbed it off my shelf, read the ISBN off the back cover, typed it into half and pressed enter. The book came up: Item: Introduction to Quantum Mechanics by David Griffiths (2004, Hardcover) : David Griffiths (Hardcover, 2004) Because that's what the book is. I used it in college as the prescribed textbook to my QM class ... so did the other students in the class. Now I mailed it asap (as my customer service is important for me and I have a perfect, although small ~20ish stars, ebay rating). The guy that bought it received it and then immediately demanded a refund saying that: "The description of the book has you assume that you are selling the retail version of "Introduction to Quantum Mechanics", 2nd Ed by Griffiths. I don't care if the the content is the same, this is not the same book. It looks like a old library book that you slapped a cover onto. I don't really appreciate being mislead. I would like a full refund and the cost of shipping it back to you paid for." I'm not sure what he's getting at. Are there many different versions of this textbook that share the same ISBN? I know that all of us in the class used this same book and we didn't have an instructor's version or something like that ... I also know that I didn't have/sell the "international version" because that one is paperback and international versions say stuff like "Not for sale in the United States", and usually have a different ISBN, plus I BOUGHT THIS FROM A BOOKSTORE FOR MY CLASS. So basically, I'm wondering, how is what I sold not what was described? Any help shedding some light on this? Is this guy crazy? Trying to scam me? Should I refund? Should I stand my ground and risk a blemish on my perfect Half/Ebay rating?