ORA-06530: Reference to uninitialized composite

After upgrading to 8.1.7, we're getting this error ([Microsoft][ODBC driver for Oracle][Oracle]ORA-06530: Reference to uninitialized composite
ORA-06512: at "ANMSAPP.PKG_T_ACCT_NBR", line 192 ORA-06512: at line 1) at inconsistent times. The system will go weeks without a problem, then we'll see the error 10 times in one day. I have not been able to recreate the error in our test environment (also 8.1.7). I've posted the package and package body below. If anyone has any ideas, it would be very helpful. Thanks!

CREATE OR REPLACE PACKAGE pkg_t_acct_nbr AS
TYPE t_ordr_id IS TABLE of NUMBER(10)

INDEX BY BINARY_INTEGER;
TYPE t_acct_nbr_nbr IS TABLE of NUMBER(7)
INDEX BY BINARY_INTEGER;

o_ordr_id	OUT	t_ordr_id,
o_acct_nbr_nbr	OUT	t_acct_nbr_nbr,
o_acct_nbr	OUT	t_acct_nbr,
o_rej_ind	OUT	t_rej_ind,
o_print_ind	OUT	t_print_ind);

o_ordr_id	OUT	t_ordr_id,
o_acct_nbr_nbr	OUT	t_acct_nbr_nbr,
o_acct_nbr	OUT	t_acct_nbr,
o_rej_ind	OUT	t_rej_ind,
o_print_ind	OUT	t_print_ind)

IS
CURSOR acct_nbr_cur IS
SELECT

	ordr_id,
	acct_nbr_nbr,
	acct_nbr,
	rej_ind,
	print_ind

rownumber NUMBER DEFAULT 1;
BEGIN
FOR row IN acct_nbr_cur
LOOP

	o_ordr_id(rownumber) := row.ordr_id;
	o_acct_nbr_nbr(rownumber) := row.acct_nbr_nbr;
	o_acct_nbr(rownumber) := row.acct_nbr;
	o_rej_ind(rownumber) := row.rej_ind;
	o_print_ind(rownumber) := row.print_ind;
	rownumber := rownumber + 1;