Simultaneous-Use problem

[PD]

Dear all,

We has the problem regarding the above subject...
mysql> select * from radgroupcheck;
+----+-----------+------------------+----+-------+
| id | GroupName | Attribute        | op | Value |
+----+-----------+------------------+----+-------+
|  1 | POSTPAID  | Simultaneous-Use | == | 1     |
|  2 | PREPAID   | Simultaneous-Use | == | 1     |
+----+-----------+------------------+----+-------+
2 rows in set (0.01 sec)
mysql> select * from usergroup;
+----------+-----------+----------+
| UserName | GroupName | priority |
+----------+-----------+----------+
| thomas   | POSPAID   |        1 |
| christie | POSPAID   |        1 |
+----------+-----------+----------+
2 rows in set (0.01 sec)

and at sql.conf..
..
# Uncomment simul_count_query to enable simultaneous use checking
# simul_counT_query = "SELECT COUNT(*) FROM ${acct_table1} WHERE
UserName='%{SQL-User-Name}' AND AcctStopTime = 0"
simul_count_query = "SELECT COUNT(*) FROM ${acct_table1} WHERE
UserName='%{SQL-User-Name}' AND AcctStopTime = 0"
simul_verify_query = "SELECT RadAcctId, AcctSessionId, UserName,
NASIPAddress, NASPortId, FramedIPAddress, CallingSta
tionId, FramedProtocol FROM ${acct_table1} WHERE
UserName='%{SQL-User-Name}' AND AcctStopTime = 0"
..

But.. the same user id still able to login at the same time on different
terminal / pc

I already try to change the op on radcheck from '==' become ':=' or
'=' but the same problem still persist

What could be wrong ?

TIA

PD