This is because you have a specific menu item for "Hammer". VM finds that and creates a different breadcrumb. This is intended behaviour.
Of course, we can talk a lot about how breadcrumbs should be handled in this case, and different VM users can have different opinions, but this is definitely not a bug.
I think we already have done a step forward in not having duplicated breadcrumbs items; unless other critical bugs are reported, this is not gonna be changed again before 1.1.6 release.