Long story, but we need to void an invoice so we can add a couple items to the sales order which would be re-opened by voiding the invoice.  The sales order is closed, but when we tried to void the invoice we get this message: "The original SO (number XXXXX) has some line items marked to be released.  This invoice cnanot be voided until these lines are marked as non-released or are in fact invoiced."
 
How can this be?  The SO is closed, but we can't void the invoice to re-open it.
 
Paul