30494: session setup failed: ERRDOS

Hi,
on a Linux RED HAT I issue the following to mount a shared filesystem on a Win server 2003 and it fails :

[root@ ~]# smbmount //172.16.0.42/eb_depot /mnt/eb_depot -o username=domaine/Administrateur rw
Password:

30494: session setup failed: ERRDOS - ERRnoaccess (Access denied.)
SMB connection failed

Thank you.