Reservations & Negative Stock

Hi, We recently implemented reservations and are happy with the benefits it has brought us. However we have a problem with some items that had negative stock inventory at the time we implemented it. For example we have one item that has an inventory of -7 which is made up of a positive adjustment with a remaining quantity of 12 and a sale with a remaining quantity of -19. When one of our sales staff entered an order for 12 of the item, Navision auto-reserved the 12 items ignoring the negative 19. We are therefore in the situation of reserving stock we don’t have. I think we need to somehow run a procedure to locate the items affected, cancel any reservations on them and (in this example) apply the positive 12 entry to the negative 19 entry. Is this correct? Can anybody suggest the best solution? We have developers available. Any help appreciated, Jonathan