Menu does not generate breadcrumbs unless node is in Navigation menu

Don't know if this is a bug, or is intended, but it wasn't an issue in versions 4 and 5.

- Create a node and place it off a parent menu item in the Navigation menu, view the node and breadcrumbs are displayed correctly. ("Home > Parent Node")

- Create a node and place it off a parent menu item in (for example) the Primary Links menu, view the node and breadcrumbs are displayed incorrectly ("Home")

The same occurs if you place the node's menu item in any menu other than Navigation. Only nodes with menu items off the Navigation menu generate breadcrumbs.