[Samba] Can't join samba4 as domain controller

[Juan Pablo Lorier]

Hi,

I'm trying to join samba 4 alpha 20 to my windows 2003 AD domain and I get this error:

Adding SPNs to CN=SAMBADC1,OU=Domain Controllers,DC=montecarlotv,DC=com,DC=uy
Setting account password for SAMBADC1$
Enabling account
Calling bare provision
Join failed - cleaning up
checking sAMAccountName
Deleted CN=SAMBADC1,OU=Domain Controllers,DC=montecarlotv,DC=com,DC=uy
Deleted CN=NTDS Settings,CN=SAMBADC1,CN=Servers,CN=Nombre-predeterminado-primer-sitio,CN=Sites,CN=Configuration,DC=montecarlotv,DC=com,DC=uy
Deleted CN=SAMBADC1,CN=Servers,CN=Nombre-predeterminado-primer-sitio,CN=Sites,CN=Configuration,DC=montecarlotv,DC=com,DC=uy
ERROR(exceptions.NameError): uncaught exception - global name 'all' is not defined
  File "/usr/local/samba/lib64/python2.4/site-packages/samba/netcmd/__init__.py", line 160, in _run
    return self.run(*args, **kwargs)
  File "/usr/local/samba/lib64/python2.4/site-packages/samba/netcmd/domain.py", line 179, in run
    machinepass=machinepass)
  File "/usr/local/samba/lib64/python2.4/site-packages/samba/join.py", line 964, in join_DC
    ctx.do_join()
  File "/usr/local/samba/lib64/python2.4/site-packages/samba/join.py", line 870, in do_join
    ctx.join_provision()
  File "/usr/local/samba/lib64/python2.4/site-packages/samba/join.py", line 598, in join_provision
    dns_backend="NONE")
  File "/usr/local/samba/lib64/python2.4/site-packages/samba/provision/__init__.py", line 1704, in provision
    sitename=sitename, rootdn=rootdn)
  File "/usr/local/samba/lib64/python2.4/site-packages/samba/provision/__init__.py", line 507, in guess_names
    if not valid_netbios_name(netbiosname):
  File "/usr/local/samba/lib64/python2.4/site-packages/samba/__init__.py", line 310, in valid_netbios_name
    return all([is_valid_netbios_char(x) for x in name])

It's on a Centos 5.6 server. I've removed everything from samba3 as told by a post I found with the same error, but still nothing.
Any one had already this problem?
Where can I get more info on the join failed part to find out what is failing?
Regards,