Authentication polling?

Hello all.

Does Samba 2.2.4 do any kind of polling to keep track of a users
authentication during a connection?
I.e. if I connect to a Samba share and do nothing with it over night,
will Samba
poll the PDC during the night to determine if my account is still valid?

For that matter, does Samba poll for anything during a long duration
connection?

I'm trying to find out just what caused some over night errors I've
seen.

Thanks.
Daniel