Thread_overrun error

[Caner YILMAZ]

CREATE PROCEDURE fetchyapisi()
BEGIN

DECLARE l_account_id BIGINT;
DECLARE l_order_id BIGINT;
DECLARE l_total_sum BIGINT;
DECLARE l_debt_sum BIGINT;
DECLARE siparis CURSOR FOR

SELECT account1_id,order_id,total_sum,debt_amount from jaces_fieldmark where account1_id=35474;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET @not_found_credit=1;
OPEN siparis;
SET @not_found_credit=0;
dept_loop:WHILE(@not_found_credit=0)DO
FETCH siparis INTO l_account_id,l_order_id,l_total_sum,l_debt_sum;
IF @not_found_credit = 1 THEN
LEAVE dept_loop;
END IF;
SELECT l_account_id,l_order_id,l_total_sum;
END WHILE dept_loop;
close siparis;
SET @not_found_credit=0;
END//

This is my procedure.When I call this I'm getting an 1436 thread stack overrun error..Also I writed thread_stack=256K in the my.cnf file...But did not improve..
Can you help me please... thank you..