ORA-01722: invalid number when you SELECT on WF_ITEM_ATTRIBUTE_VALUES

SQL> select rownum from apps.WF_ITEM_ATTRIBUTE_VALUES
where item_type='HXCEMP' and item_key=120
SQL> /

ROWNUM
----------
1
2
3
4
5
6
7
8
9
10
11

ROWNUM
----------
12
13
14
15
16
17
18
19
20
21
22

ROWNUM
----------
23
24
25
26
27
28
29
30
31
32
33

ROWNUM
----------
34
35
36
37
38
39
40
41
42
43
44

ROWNUM
----------
45
ERROR:
ORA-01722: invalid number

SQL> select count(*) from wf_item_attribute_values;

COUNT(*)
----------
53014588

Metalink note 179260.1 says:

The column WF.ITEM_KEY can not be alphanumeric for upgraded order lines. It
stores the to_char(line_id) into it. ONT00065.sql should never for fail for
any records with ITEM_TYPE = 'OEOL'. Alphanumeric records will cause upgrade
errors.

However we dont have OEOL item type.

SQL> select name, number_value
2 from wf_item_attribute_values
3 where item_key=120;

NAME NUMBER_VALUE
------------------------------ ------------
ERROR_ACTIVITY_ID
ERROR_ACTIVITY_LABEL
ERROR_ASSIGNED_USER
ERROR_ITEM_KEY
ERROR_ITEM_TYPE
ERROR_MESSAGE
ERROR_MONITOR_URL
ERROR_NAME
ERROR_NOTIFICATION_ID
ERROR_PERSON_ID
ERROR_PERSON_USERNAME

NAME NUMBER_VALUE
------------------------------ ------------
ERROR_RESULT_CODE
ERROR_STACK
ERROR_TYPE
ERROR_USER_KEY
ERROR:
ORA-01722: invalid number

Still investigating this one.