In order to use Breadcrumbs NavXT to display the title of a gallery, you need to create a new gallery subpage that the gallery will link to.
Is there a way to make NextGen automatically create this gallery subpage named by the title of the gallery?
In gallery settings there is an checkbox option called "Deactivate gallery page link:" When that is checked "The album will not link to a gallery subpage. The gallery is shown on the same page. " You may have already done it but if not uncheck it if its checked and see what happens.