Solution or Workaround
Exporting orders to Access produces two extra orders called 'start' and 'finish'.
Locations are being copied along with the orders, which Access interprets as orders. When imported back into ArcLogistics Route, these additional orders will need to be deleted, though the original locations will remain intact.
To prevent the creation of these additional orders, when you select orders to be exported to Access, be sure not to include the locations.