It's issue in NAV 2009 R2.
When a DROP shipped order is refused by the customer and needs to be returned direct to the supplier (entities where there is no Warehousing) inventory Is brought into the system in foreign entities (though no physical holding) by the Sales Return process.
This is mainly done via Sales credit memos raised by Billing for raising a credit but it ends up with inventory brought into the entities inflating inventory valuations.
The sales credit memo activity needs to be either linked to the Sales Return thus reversing the DROP ship sales and automatically having a linked Purchase Return to enable procurement to ship off the inventory via the Purchase Return.
Better so if this could be automated when a sales credit is authorised thus leaving no inventory for the DROP shipped orders.
Where Warehousing is enabled there should be an option for an Sales Return where a user could manually create a Purchase Return (from the Sales Return) as of now this is not possible due to reservation entries for the Sales Return document that doesn’t allow the Purchase Return to be shipped.