It shouldn't allow you to post more than one copy of the book. Have a look at your bookshelf. Are both copies listed?

Sounds like a message bug. You might want to report it to R&R and have them check on it. :)

I have seen duplicates on people's shelf, have wondered if the rules about posting duplicates had changed.

Same thing happened to me the other day so I alerted R & R but haven't heard anything yet. I now keep my list sorted by date and check to make sure the book was posted.

I have had 2 of the same book, and what I've done is just post one copy.  Then once that one is taken I go ahead and post the 2nd copy.

it's possible that those that have dupes on their shelf have different bindings/ISBN's.  maybe they have the hardback and paperback. 

Willa, Leslie has the right answer. The only way to have to copies of a book on your shelf (without a glitch of some sort) is to have two copies that have different ISBNs. You cannot post the same ISBN twice to your shelf.

BUT, I believe it does tell you sometimes that it is posting it, if I recall correctly, even tho it really isn't. I wonder if it changes the posted date and your place in the FIFO line when it does that?

I have 2 copies of the same title, but they are different ISBNs.

I wonder if the error being missing is why I discovered two copies of the same ISBN on my physical shelf-I wish it had told me the second wasn't being listed.

Do you have to wait until the first book is marked received before you can post the 2nd, or can you post the second copy as soon as the first is requested?  I'm in that situation now--just mailed the first copy and wondering if I need to wait...  :)

Patricia, Mine were all taken in Box swaps, but as soon as I accepted the swap and the book was automatically removed from my shelf I was able to post the second copy.  So if you accepted the request and PBS automatically removed the book from your shelf, you should, based on my experience, be able to post that 2nd copy.

And BTW, I read your post on the lost books thread about weather delays.  I'm in NJ, and I can tell you that last Friday we got several inches of snow and the airports around here (Philly, Newark, JFK, LaGuardia) were indeed on all sorts of delays and cancellations.

Patricia, as soon as you mark a book mailed you can post another copy.  I did this when I had 3 copies of a heavily WL'd book. 

Again?!  Ugh, don't tell me that I'll never get my books!!  :-p  And my boys said for ya'll to stop stealing all our snow, LOL!  ;)  They are so disappointed, this is the 2nd year in a row we have gotten zero snow in our part of Germany.  I've got hyacinths halfway up this year, and it's not even March yet!!

Tell the boys that we didn't steal anything--that was our first snow this year, which is practically unheard of!!!  Usually we have snow way earlier than the end of Feb.  But the airports have been all straightened out for days now...I think they were only interrupted for 2 days max.  Although I delayed getting to the PO and mailing my books out because of it, but only for a day.