SQL accounting & wrong order

Hi.
There is a trouble in my SQL accounting.
Sometimes I see in my 'radius.log':

Mar 24 21:03:03 Acct.info: login: entry for NAS 10.2.254.250 port 2059 wrong
order

It seems that acct-start and acct-stop packets following in wrong order and
I see in the 'detail':

Thu Mar 24 21:02:36 2005
	Acct-Session-Id = 00002488
	Acct-Terminate-Cause = User-Request
	NAS-Port-Id = 2059
	Acct-Status-Type = Stop

Thu Mar 24 21:03:03 2005
	Acct-Session-Id = 00002488
	NAS-Port-Id = 2059
	Acct-Status-Type = Start

Finally, active session remaining in the database.

'config' file:

auth {
        port 1812;
        max-requests 127;
        request-cleanup-delay 2;
        detail yes;
        strip-names yes;
        checkrad-assume-logged yes;
        reject-malformed-names no;
};

acct {
        port 1813;
        max-requests 127;
        request-cleanup-delay 0;
        detail yes;
        system yes;
};

Please help me resolve this problem.
Best regards,
Sergey