[Samba] Samba Invalid user not working

[updatemyself .]

Thanks a Lot Chris & ALL,

in my ADS around 2500 Users are there..
by adding the "@Domain Users" i am giving permission to all
and every month.. around 100 new users and some resign are there..
while create a user.. by default windows 2003 ADS adding that user to
"Domain Users" group... adding him/her to another particular group
just for.. this case is not such easy ...... if its a One time.. job..
SURE.. i will do it..
but i have to make sure it.. each and every time.. while i add new users to
my ADS
and all this doing.. only to remove two users from one service..samba
this will be a cracking way... i think

if "invalid users" working proper... whats the point to do this...
that's y i am searching for a smart option...
let me know.. any one already reported this as BUG....