duplicate acctuniqueid problem

[d tbsky]

Hi:
   I am testing 802.1x accounting under fr 3.0.8. steps below:

1. use my notebook to login AP. accounting begin.
2. poweroff/poweron the AP. AP send "Accounting on". and previous
accounting log closed with "NAS-Reboot".that's good.
3. use my notebook to login AP. fr can not create a new accounting
entry, it seems "Acct-Session-Id" will be reused and cause
"acctuniqueid" duplicate. error message like below:

(11) sql: rlm_sql_mysql: ERROR 1062 (Duplicate entry
'e8db0ea9accf3a44b835ff8a0e5b62c0' for key 'acctuniqueid'): 23000
(11) sql: SQL query returned: need alt query
(11) sql: Trying next query...
(11) sql: EXPAND UPDATE radacct SET acctstarttime       =
FROM_UNIXTIME(%{integer:Event-Timestamp})...................

then fr will try to update an existing entry instead of log a new entry.

is the behavior expected? how can I setup to prevent it?
thanks a lot for help!

Regards,
tbskyd