PL/SQL :: Oracle Exchange Partition Feature Not Working As Expected?

I used the Exchange Partition feature to swap segments between 2 tables- one Partitioned, and one Non-Partitioned. The exchange went well. However, all the data in the partitioned table has gone to the partition which stores the maxbound values.

/** actual table names changed due to client confidentiality issues */

-- Drop the 2 intermediate tables if they already exist

drop table ordered_inv_bkp cascade constraints ;
drop table ordered_inv_t cascade constraints ;
/**

1st create a Non-Partitioned Table from ORDERED_INV and then add the primary key and unique index(s):

*/
create table ordered_inv_bkp as select * from ordered_inv ;
alter table ordered_inv_bkp add constraint ordinvb_pk primary key (ordinv_id) ;
--
create unique index ordinv_scinv_uix on ordered_inv_bkp(
SCP_ID ASC,

[code]....

-- Next, we have to create a partitioned table ORDERED_INV_T with a similar

-- structure as ORDERED_INV.

-- This is a bit tricky, and involves a pl/sql code

declare
l_dt_start DATE;
l_ptn VARCHAR2(50);
cnt PLS_INTEGER;
l_cnt_initial PLS_INTEGER;
ts_name VARCHAR2(50);
l_sql VARCHAR2(10000);
ts_indx VARCHAR2(100);

[code]....

-- Add section to set default values for the intermediate table OL_ORDERED_INV_T

FOR crec_cols IN (
SELECT u.column_name ,u.nullable, u.data_default,u.table_name
FROM USER_TAB_COLUMNS u WHERE
u.table_name ='ORDERED_INV' AND
u.data_default IS NOT NULL )
LOOP

[code]....

-- Next, use exchange partition for actual swipe

-- Between ordered_inv_t and ordered_inv_bkp

-- Analyze both tables : ordered_inv_t and ordered_inv_bkp

BEGIN
DBMS_STATS.GATHER_TABLE_STATS(OWNNAME => 'HENRY220', TABNAME => 'ORDERED_INV_T');
DBMS_STATS.GATHER_TABLE_STATS(OWNNAME => 'HENRY220', TABNAME =>'ORDERED_INV_BKP');
END;
/
SET TIMING ON;

[code]....