User never get disconnected (was Re: Simultaneous-Use problem)

[PD]

On 4/12/2007, "Milan Holub" <holub at thenet.ch> wrote:
.cut...
>==> I believe you have a typo in the tables:
>radgroupcheck: groupname=POSTPAID
>usergroup: groupname=POSPAID

I still have another problem...
many of radacct table records are incompleted.
We know the user already disconnected (even by click logout botton or
just shut his/her computer down), but the information did not saved.

At Radacct table, many previous records with the same mac address and
user name still get connected.

Questions..
+ what cause of this problem ?
+ how to delete this entry daily (perhaps with crontab)

TIA

PD