Parsing folder problem with parantheses

The following SQL is changed in DDerl to something which breaks the Oracle parser:

    SELECT   /*+ NO_INDEX(BDETAIL2) */
             TO_CHAR (ADD_MONTHS (SYSDATE, -1), 'YYYYMM'),
             CON_CODE,
             COUNT(*),
             SUM (BD_IW_AMOUNT)/COUNT(*),
             SUM (BD_IW_AMOUNT),
             BD_IW_CURID
    FROM     BDETAIL2, CONTRACT
    WHERE    CON_ID = BD_TOCID
             AND CON_ESID = 'A'
             AND CON_ID <> 'FIXNETTOC'
             AND NVL (CON_VIRTUAL, 0) = 0
             AND BD_DATETIME >= ADD_MONTHS (TRUNC(SYSDATE,'MONTH'), -1)
             AND BD_DATETIME < ADD_MONTHS (TRUNC(SYSDATE,'MONTH'), 0)
             AND BD_MAPSID = 'R'
             AND BD_CDRTID NOT IN ('SMS-EXT','PAGER-EXT')
             AND BD_STATUS = '0'
             AND BD_IW = '1'
             AND BD_IW_DIR = 'O'
    GROUP BY CON_CODE, BD_IW_CURID
    UNION ALL
    SELECT   TO_CHAR (ADD_MONTHS (SYSDATE, -1), 'YYYYMM'),
             CON_CODE,
             0 smscount,
             ciote_price + 0.0,
             0 amount,
             ciot_curid
    FROM     contract,
             coniot,
             coniote
    WHERE    CON_ESID = 'A'
             AND CON_ETID = 'TOC'
             AND CON_ID <> 'FIXNETTOC'
             AND NVL (CON_VIRTUAL, 0) = 0
             AND con_datestart < ADD_MONTHS (TRUNC (SYSDATE, 'MONTH'), 0)
             AND (con_dateend > ADD_MONTHS (TRUNC (SYSDATE, 'MONTH'), -1) OR con_dateend IS NULL)
             AND NVL (CON_VIRTUAL, 0) = 0
             AND ciot_id = ciote_ciotid
             AND ciot_conid = con_id
             AND ciot_trctid IN ('SMS')
             AND ciot_iwdid IN ('ORIG')
             AND NOT EXISTS
                (SELECT ROWID FROM BDETAIL2
                 WHERE  CON_ID = BD_TOCID
                 AND BD_DATETIME >= ADD_MONTHS (TRUNC(SYSDATE,'MONTH'), -1)
                 AND BD_DATETIME < ADD_MONTHS (TRUNC(SYSDATE,'MONTH'), 0)
                 AND BD_MAPSID = 'R'
                 AND BD_CDRTID NOT IN ('SMS-EXT','PAGER-EXT')
                 AND BD_STATUS = '0'
                 AND BD_IW = '1'
                 AND BD_IW_DIR = 'O')
    GROUP BY CON_CODE,
             ciote_price,
             ciot_curid
    ORDER BY
        1,
        2,
        4,
        6

is corrupted into :

    (SELECT /*+ NO_INDEX(BDETAIL2) */
        TO_CHAR(ADD_MONTHS(SYSDATE, - 1), 'YYYYMM'), CON_CODE, COUNT(*),
        SUM(BD_IW_AMOUNT) / COUNT(*), SUM(BD_IW_AMOUNT), BD_IW_CURID
    FROM
        BDETAIL2,
        CONTRACT
    WHERE
        CON_ID = BD_TOCID
        AND CON_ESID = 'A'
        AND CON_ID <> 'FIXNETTOC'
        AND NVL(CON_VIRTUAL, 0) = 0
        AND BD_DATETIME >= ADD_MONTHS(TRUNC(SYSDATE, 'MONTH'), - 1)
        AND BD_DATETIME < ADD_MONTHS(TRUNC(SYSDATE, 'MONTH'), 0)
        AND BD_MAPSID = 'R'
        AND NOT (BD_CDRTID IN ('SMS-EXT', 'PAGER-EXT'))
        AND BD_STATUS = '0'
        AND BD_IW = '1'
        AND BD_IW_DIR = 'O'
    GROUP BY
        CON_CODE, BD_IW_CURID)
UNION ALL
    (SELECT
        TO_CHAR(ADD_MONTHS(SYSDATE, - 1), 'YYYYMM'), CON_CODE, 0 smscount,
        ciote_price + 0.0, 0 amount, ciot_curid
    FROM
        contract,
        coniot,
        coniote
    WHERE
        CON_ESID = 'A'
        AND CON_ETID = 'TOC'
        AND CON_ID <> 'FIXNETTOC'
        AND NVL(CON_VIRTUAL, 0) = 0
        AND con_datestart < ADD_MONTHS(TRUNC(SYSDATE, 'MONTH'), 0)
        AND (con_dateend > ADD_MONTHS(TRUNC(SYSDATE, 'MONTH'), - 1)
        OR con_dateend IS NULL)
        AND NVL(CON_VIRTUAL, 0) = 0
        AND ciot_id = ciote_ciotid
        AND ciot_conid = con_id
        AND ciot_trctid IN ('SMS')
        AND ciot_iwdid IN ('ORIG')
        AND NOT (EXISTS
        (SELECT
            ROWID
        FROM
            BDETAIL2
        WHERE
            CON_ID = BD_TOCID
            AND BD_DATETIME >= ADD_MONTHS(TRUNC(SYSDATE, 'MONTH'), - 1)
            AND BD_DATETIME < ADD_MONTHS(TRUNC(SYSDATE, 'MONTH'), 0)
            AND BD_MAPSID = 'R'
            AND NOT (BD_CDRTID IN ('SMS-EXT', 'PAGER-EXT'))
            AND BD_STATUS = '0'
            AND BD_IW = '1'
            AND BD_IW_DIR = 'O'))
    GROUP BY
        CON_CODE, ciote_price, ciot_curid
    ORDER BY
        1, 2, 4, 6)

If adding parantheses is really neccessary, then the order by clause must be outside of it.