i ordered a book on 1/17 and waited for the person to send. it was never marked mailed so it moved on to the next sender and they accepted and printed. this morning i got this message from the original member who didn't mark their copy mailed.

I mailed this book, Class President, but neglected to mark it mailed before the deadline, and it was canceled. If you have an active request on your account page for Class President, it is not with me--it is with a new sender. Your request must have been passed on to that person, and you will get 2 copies of this book if the new request is not canceled. If you do have an active request on your account page for this book can you cancel it? You will be getting a copy of the book from me. You can then mark my book received when it arrives, from your Transaction Archive. If you are willing to do this I really appreciate it! Just let me know if you have a new transaction on your account page, and if you are able/willing to cancel. I am very sorry about the inconvenience. I am going to mark my books mailed before the deadline from now on! Thank you very much!

so now that the second member has already accepted and printed I can't cancel the transaction. I don't want 2 copies of the same book and i don't want to loose a credit for a second copy of the same book because of another members mistake as i don't think that's fair. so what can i do?

You are under no obligation to mark the first book as received.  It's up to you what you do.

You can try this ... send a PM to the new sender, the one on your My Account page. Explain in the message that the request was automatically passed along to her because the first person did not mark her book malied and therefore you are wondering if she'd be willing to ask PBS to cancel the request if she has not yet mailed the book. Ask her to please not click any "cancel" buttons she sees on her screen because that would just roll the request over to the next sender and remove the book from her shelf.

Instead, she should use the Contact Us link at the bottom of the page under Company and tell the PBS Team that the requester has asked her to cancel the transaction and she would like them to do so in a way that puts the book back on her shelf and prevents the requester from getting another copy.

There are a couple of risks with this approach. The second sender may not pay attention to what you write and she might click the Cancel button. This means your request will roll over and you'll need to try to cancel that one before the sender accepts or go through the whole thing again. Or, the PBS team might not see the second sender's feedback message in time and the transaction might automatically cancel, leading to the same problem. You'll need to keep a close watch on your My Account page for the next few days.

If you do end up getting two copies of the book, then the only one you mark received is the one on your My Account page. If you are able to stop the second book from coming then you do have to mark the first book received from your Transaction Archive.

I'd tell the original sender that I cannot cancel the 2nd transaction because they have already printed the mailing label.  I'd offer to send their book back to them if they wanted to buddy me a credit and their mailing address.  If they didn't want to do that and get the book back, I would just not mark it received.

This is the official way to handle the situation.

From the Help Center:

http://www.paperbackswap.com/help/help_item.php?id=145

Remember--it is not your responsibility to fix their mistake.

Try Cathy's suggestion above.  It's worth a shot.  If the new sender is not willing to contact the Admin Team to have them cancel the new transaction, and you receive two copies of the book, then you do not have to mark the canceled book received.

thanks for all the helpful and great advice. 

I'm curious, if the sender has PBS cancel the transaction, do they lose their place FIFO?  

That is why the suggestion is to contact TPTB. They can do it behind the scenes so that the second sender doesn't lose their place.

if the SENDER cancels transaction, they lose FIFO... if PBS knows whole story, they can fix it all.  but like others said, it is NOT your fault, nor your responsibility.  The system is set up to allow plenty of time for the sender to respond (which irritates some others, when waiting for books that continually roll over at 6 day intervals!) BUT, that is the way the system is.  Tries to be fair enough for all!!

On my very first request here at PBS, the first sender forgot to mark the book received so I ended up with two copies of the book.  What I did was ask the first sender if she wanted to order a book from my shelf, then I'd return the book she sent with the book from my shelf.  I figured it may cost a few pennies extra to mail two books instead of one, but that way she'd hopefully be able to get a "new to her" book along with the book I was returning.  But, before you do something like this, I'd wait until you have both copies of the book you ordered in hand--to make sure you end up with a good copy!
 

if the SENDER cancels transaction, they lose FIFO... if PBS knows whole story, they can fix it all

I knew the sender would lose their place in a normal cancellation, but if there are other circumstances involved, if PBS cancelled it, would the sender then lose their place was my original question.

I wouldn't take the chance, myself.

The original sender was very gracious, but it was her mistake.  Other people shouldn't have to pay for it.  I would simply PM her and ask her to buddy a credit and have the first book sent back.

No, the sender will not lose her place if PBS cancels the transaction and leaves the book on the sender's shelf. They can also cancel it and remove the book and roll the transaction over to the next sender; so the sender who asks to have it canceled needs to make it clear that the requester is asking her to have the transaction canceled and she agrees to that.

In a situation like this, the Admin Team cancels the transaction as if the requestor were canceling the second transaction (which the requestor can't do, since the address label has been accessed.)  In this way, the sender doesn't lose his place in the sending line, and the requestor's order is not passed on to a new sender.