Book Module : New book project from duplicate book

When I begin a new book project I generally dublicate an existing book, select it as the Target collection and then remove all the photographs from the filmstrip before adding new ones. This use to work fine but I have noticed that now when I do the same process  and subsequently change the layout of a page that the original photos reappear. I then have to remove these photos from the target collection again.

This does not impede the creation of my book but is slightly annoying! 

Any solutions?

[Moved from ‘Bugs’ to ‘Discussions’ by moderator, according to forum rules. A ‘bug’ is not just another word for any problem with software!]