samba - Sep 2009 - Samba quota

Hi,

i have a problem regarding smbcquota..when i try to set the quota using
smbcquota an error will come out :

error:
failed session setup with NT_STATUS_LOGON_FAILURE
cli_full_connection failed! (NT_STATUS_LOGON_FAILURE)

i hope you guys can help me with this. Is there any other configuration so that
i can set quota to directory of samba user? my smbcquota version is
3.0.28-1.el5_2.1.

Thank you in advance.

Regards,
nik