Egg Bramhill - The check box was checked throughout the life of this web until V15 changed it.
Tam, can you supply a file in which V15 changed this behaviour? If the checkbox is ticked it creates a navbar that creates links to all pages within the site as you've found out yourself. That's why I highlighted the site navigation bar option.

Delete a page from the navbar sub. Right click Repeat on all pages. The change is only made on that page all the others are still as they were. So does not work.
I'm just trying to understand your the problem you have. I've never come across an issue were deleting a navbar link didn't delete all similar links ???