Getting Error "String index out of range: -1" on simple insert statement

Hello,

I'm executing a simple insert statement (please see query below) using DB2 8. On AS400. Statement runs successfully if it doesn't find any rows to insert, it returns error "String index out of range: -1". I'm using iSeries navigator to connect to AS400.

If anyone came across such issue and/or has any suggestion I'd appreciate it.


Thanks in advance.
Abhijit

-- Query --

INSERT INTO CO_BAL_TYPE (
Company_ID,
Balance_Type_ID,
Orig_Bal_Type_ID,
Description,
created_time,
created_by_user_ID,
modify_by_user_ID,
modify_time,
deactivation_date,
bal_subtype
)

SELECT
Company_ID,
( SELECT max(balance_type_iD)+1
FROM co_bal_type
WHERE company_ID = t1.Company_ID
),
Balance_Type_ID,
'DPA - ' || Description,
timestamp(current date, current time),
created_by_user_ID,
modify_by_user_ID,
timestamp(current date, current time),
deactivation_date,
'DPA'
FROM
CO_BAL_TYPE t1
WHERE
bal_subtype is null
AND balance_type_ID > 0
AND NOT EXISTS (
SELECT 1
FROM
CO_BAL_TYPE
WHERE
Company_ID=t1.Company_ID
AND orig_bal_type_ID=t1.balance_type_ID
AND bal_subtype = 'DPA'
);
--
-- End of script