PTO FastFormula calculates Leap Year carryover incorrectly

Our PTO FastFormula calculates Leap Year carryover incorrectly for people that have an anniversary date of 2/28. The carryover amount is zero for 2/28/12, instead of the actual accrual carryover. All other employees have correct carryover balances.

Does anyone have any suggestions?  See formula below.

Thank you.

Bruce Saunders

 /* ------------------------------------------------------------------------
    NAME : NON_UNION_ACCRUAL_CARRYOVER
    Formula Type: Accrual Carryover
    This formula uses the seeded carryover formula for our
    hire date anniversary accrual plan
   ---------------------------------------------------------------------*/

DEFAULT FOR ACP_SERVICE_START_DATE IS '4712/12/31 00:00:00' (date)
DEFAULT FOR ACP_CONTINUOUS_SERVICE_DATE IS '4712/12/31 00:00:00' (date)
Default for EMP_PER_HIRE_DATE is '4712/12/31 00:00:00' (date)