samba - Nov 2003 - Cannot join domain: unable to find suitable driver

Hi everybody!
I just installed the latest samba release, I'm trying to attach it to a
Win2K based domain, I'm guiding myself with samba-howto collection, more
accurate..with chapter 21 winbind: use of domain accounts.
In the point 21.5.3.4: Join the samba server to the pdc domain I execute
in the command line the following:

root#:/usr/local/samba/bin/net rpc join -S PDC -U <my_user_name>

and I get the following error:

"Unable to find a suitable driver"

Already modified the smb.conf file and the krb5.conf file.
Any idea that must generating this error?