R12.1.3: Cannot unreserve PO to allow changing charge accounts

While you can modify the amounts in the Oracle Purchasing Forms, the document "Unable To Un-reserve PO’s From Buyers Workbench To Allow Changing Charge Account" from article ID 1957711.1 shows us that the amounts cannot be changed via the Buyer Work Center due to a validation check on the html page and what patch will resolve the issue.