'Line Error - The tax code you have entered is invalid' when resubmitting a previously withdrawn exp

Hi - we are investigating error in iE where users get Line Error when they have submitted an expense report, withdrawn it and are trying to resubmit it. Document 313139.1 gives indication that our error could be because the Expense Report start date is earlier than the Tax Code start date in AP_TAX_CODES_ALL table. When I query this table it shows CREATION_DATE and LAST_UPDATE_DATE columns only. Here the values for both are '08-JAN-2013'. However when I look in forms (Payables > Setup > Tax > Codes) then I can see the 'Effective Dates - From' values for same codes are '01-JAN-1952'. Am I looking in right form? How can I check and make correction of Tax Code start date?