Does anyone know why some of the book requests I recieve have the PM button and others don't? It seems odd. Sometimes I can use the pm button to see who is requesting before accepting and sometimes it doesn't show up until after I accept the request.

If it's on the 48 hour hold, waiting for them to accept, you should be able to see the PM button. But once they accept, I thought the PM button is gone until you mark that you can mail it. For books that are auto requested, the PM button isn't there until you accept the request.