WMS - strange behaviour with "Direct Put-away"

Tomas

NAV4.03

If we use "Direct-Putaway" on Location card (Watehouse tab), then we must fill in "Bins" tab as well. There is one interesting field "Adjustment Bin Code".

Which according to NAV help is for:

This field contains the code of the bin in which you record observed differences in inventory quantities. The bin cannot contain real items. This field is only available if you are using directed put-away and pick at this location.
The program also posts to this bin when you post an item journal, purchase invoice, purchase credit memo, sales invoice or sales credit memo.

So, the problem arises when we post Sales Credit Memo. Because then, quantity is posted to Adjusment Bin Code (which, cannot contain real items - and is always empty according to Warehouse Entry table). We end up having quantities in Item Ledger Entry, and not having them in Bin Contents - therefore we have a difference in quantities.

Anyone noticed these things happening? Any ideas whether it should work in this way? I am getting confused on for what reason Adjustment Bin Code is used. And... should it act in this way with Sales Credit Memos?

Any ideas, suggesstions?