Problems using samba as a PDC

[Pietro Regis]

Hi,
We are trying to use samba as a PDC, and we have the following problem.

We have a NT Server PDC, but it's a very old machine, so we want to
substitute it with a Linux Server runnig samba as a PDC.
All the user's profiles are stored locally on the NT Clients, and we don't
want to use roaming profiles.
The Linux Server is correctly configured as a PDC, it uses samba 2.2.1a and
has the same name and the same IP Address of the NT Server.
When we shut down the NT Server and start the Linux Server, all the NT
Clients fail when a user tries to log into the domain, and we see the
following error:

The system cannot log you on to this domain because the system's computer
account in its primary is missing or the password on that account is invalid

We succeed in logging into the domain only if we execute the following
operations:
we log into the NT Client locally as administrator;
we successfully join to a dummy workgroup and restart the PC;
we log into the NT Client as administrator;
we successfully join to the domain and restart the PC.

The problem is that if we execute these steps, when an user log into the NT
machines he has assigned the default profile, and not the local profile he
has when we use the NT Server as a PDC.

Any suggestions?

Thanks in advance.