We have an open PO for an item that is being received in small quantities over a year.  The item was originally assigned a location (not the default).  Later on, we consolidated the locations and removed all but the default location.  Still whenever this item is received in, it shows up in inventory (IN-A) in the old (now deleted)
location).  We are able to fix the problem using Maintain
Database.  It appears that when the location was deleted, open PO's (BKPPOL file) were not updated.