One book in PC library will not sync to iPad

[__Steve__]

All the books in the PC library have appeared in the iPad library automatically as soon as they are downloaded to the PC, except the last one purchased

The most recent purchase is visible and readable in the PC library but has not popped up in the iPad library after several hours

The book bought a few minutes earlier in the same way has come across to the iPad

Anyone have a clue what is happening please?

[__Steve__]

In case it helps, checked the iPad memory and there is heaps, used only 9GB of 32GB