Library reservation question

[Cachailleacha]

My DS is reading a series of books and is waiting for the next book he has reserved. He went online to check if he had moved up a position yet and he has moved from a position 2 to position 4 in the queue!

Does any one who works in a library or otherwise have any idea why this has happened? Do libraries allow people to jump the queue with reservations? He is disappointed as he could be waiting months now with transit times as well.

I think sometimes its because the copy that would have been coming to your particular library is overdue and they don't think it will be returned for a while. In our county they seem to cluster the libraries and they try to circulate within that cluster.

There one copy of the hardback that he reserved and a paperback with one copy in transit (so not missing). The list is longer for the paperback so I don't know if two people on that list both realised that the hardback list was shorter, both contacted the library and got to jump ahead? It's a first world problem I know, but just annoying.