I received a book today, but when I went to mark it "received," it wasn't in my account.  ???  I'm not sure what to do about it.  I have another book (just requested today, I think, maybe yesterday) showing as to be received, but the one that just came is not there.  (Everything else about it has proceeded as normal.)  How do I proceed?

Rachel,  What likely happened is the person who sent you the book had two going out on the same day and just switched the wrappers.  I would suggest sending her a PM and asking if that is what happened.  You can work it out once everyone knows what happened.

Hi, Rachel.

Check this from the Help Center:

• I got a book I requested, but I can't mark it received!

Is it a book you actually ordered?  It may have gone lost and was moved to your transaction archive.  You can mark it received from there. 

If it's not a book you ordered then it's probably like Ronda said and someone mixed up their books to send out. See if the name matches the one you are waiting for by clicking on the PM button.  If that's the case, then don't mark the book as received.  PM the person and tell them you got the wrong book.  They can buddy you a credit to cover postage and send you the address to send the book to the right person.  Don't mark the book you ordered as received until you actually get the book. If the book goes lost, you'll get your credit back.

It is a book I ordered.  The wrapper is correct.  And it arrived in a very timely manner.  I thought it was marked "mailed" right away, but I will double-check that. 

It's possible that the person forgot to mark the book mailed and there was no other copy in the system.  If it was a WL book, check your WL-it might be back on there because the system assumed this one wasn't sent if it wasn't marked mailed. If there were other copies in the system it would have passed the request on to another person. 

It should still be in your transaction archive though with a red mark and you can mark it received from there.