Issues with registering the Battle Pack for FOG UV

[Hoplite1963]

Hi
I already owned fog and all the existing DLC and have been able to download the game easily and activate all the packs with the possible exception of the Scenario Battle Pack. I can enter its serial number and save it but when I then exit and go back in again the serial number has vanished. However if I open up "New Game" and filter the Scenarios by "Book" the scenarios for the Battle Pack are there. I also notice that the Battle Pack is still on sale.
Is there an issue here?

Many thanks
Ian