net rpc join fails samba3.0alpha21

[Wolf-D. Perl]

Hi, i want to setup the latest samba3.0alpha21 cause we want to
migrate our ntdomain to linux. i had a well running samba2.2.3a which
i first uninstalled by deleting all samba packages from my redhat 7.3.
then i downloaded the tar.gz for the alpha21 release.
i configured with --winbind and --pam and then installed, all fine.
i am wondering about the smb.conf file, which i try to setup with
swat.
there is NO possibility to put "workgroup = ntdomain" in there!?
i want to get the linuxserver as memberserver, so i have to setup
security = domain
domain logons = no
domain master = no.
when i want to join my domain i get the error
# net rpc join -U Administrator%Password -S PDC
1] rpc_client/cli_netlogon.c:cli_nt_setup_creds(300)
cli_nt_setup_creds: auth2 challenge failed NT_STATUS_ACCESS_DENIED
1] libsmb/trust_passwd.c:just_change_the_password(41)
just_change_the_password: unable to setup creds
(NT_STATUS_ACCESS_DENIED)!
1] utils/net_rpc.c:run_rpc_command(154)
rpc command function failed! (NT_STATUS_ACCESS_DENIED)
Joined domain XXX.
when i create the machine account on pdc first and then type
"net rpc join oldstyle -S PDC", then there is no error message,
but "wbinfo -t" returns every time
checking the trust secret via RPC calls failed
error code was (0x0)
Could not check secret
(although i can do "rpcclient PDC -U Administrator")
in my log.winbindd there is every 10 seconds the error
"nsswitch/winbindd_util.c:init_domain_list(219)"
" Retrying startup domain sid fetch for ntdomain "
I tried to with "net rpc getsid" without an error, but still i
dont get my linux join the ntdomain.
in my nmbd.log i have the error
Netbios nameserver version 3.0alpha21 started.
Copyright Andrew Tridgell and the Samba Team 1994-2002
"nmbd/nmbd_responserecordsdb.c:find_response_record(233)"
" find_response_record: response packet id 12131 received with no
matching record."

here is my smb.conf:
# Samba config file created using SWAT
# from ip (ip)
# Date: 2002/12/06 15:08:51

# Global parameters
[global]
workgroup = ntdomain
netbios aliases = linux
server string = linux
security = DOMAIN
domain master = No
obey pam restrictions = Yes
password server = PDC
passdb backend = /usr/local/samba/private/smbpasswd, unixsam
pam password change = Yes
passwd program = /usr/bin/passwd %u
passwd chat = *New*password* %n\n *Retype*new*password* %n\n
*passwd:*all*authentication*tokens*updated*successfully*
unix password sync = Yes
log file = /var/log/samba/%m.log
max log size = 0
name resolve order = bcast lmhosts host wins
socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
load printers = No
dns proxy = No
wins server = ip pdc
ldap ssl = no
winbind uid = 10000-20000
winbind gid = 10000-20000
template homedir = /home/xxx/%D/%U
template shell = /bin/bash
winbind separator = +
hosts allow = xxx.xxx.xxx.0/255.255.255.0
printing = lprng

[homes]
comment = Home Directories
valid users = %S
read only = No
create mask = 0664
directory mask = 0775
browseable = No

[printers]
comment = All Printers
path = /xxx/xxxxx/samba
printable = Yes
browseable = No

[Test]
comment = TestShare RedHat7.3
path = /xxx/xxxx

Any hints?

Regards, Wolf