I requested a book last week. The person I requested it from did not mark it as mailed in time so the swap was canceled. However, they sent me a message saying that they put in the mail today. I'm guessing after it got canceled that my request went to the next person in line with the book, because now I'm apparantly getting a copy from a different member who has already printed a label and has marked it as "will mail by". What do I do?

You have a couple of things you could do.

1. Ask the 2nd person to cancel the order. If she printed the label only (without paying for DC or PBS postage), she won't be out any money yet. If she has already paid for DC or postage, then you probably shouldn't ask her. If she cancels, you would get the first book, and you can go to the Transaction Archive to mark it received when you get it.

2. Let both books come. Since the first person mailed the book but didn't mark it mailed on time, AND a second copy was ordered, you DO NOT have to mark the (first) book received when you get it. You would only mark the book mailed by the second person Received.

The second way is what the rules say to do, after you have 2 copies on the way. But since the second book isn't mailed yet, you do have a chance to cancel that second order, if the other member will let you.

Some people might say that it is rude to ask to cancel the 2nd order. I don't know, if someone asked me, and I wasn't yet out any money, I would do it to help you out. So, IMO, doesn't hurt to ask.

If it's a heavily posted book the 2nd sender might not be so inclinded to cancel the request and then end up at the end of the FIFO line.  But it can't hurt to ask. 

But like Sara says: you do not have to give the 1st person a credit since they didn't mark the book mailed. You can if you want to but you don't have too. In fact withholding the credit might teach them a lesson to mark books mailed on time.  PBS gives you up to 7 days to mark a books mailed and they send reminders out.  It also says on the listing that you might not get your credit if you fail to mark a book mailed by x date and time. So it's not like they had no warning.