samba - Jun 2003 - PDC upgraded from 2.2.7 to 3.0.0beta1, now XP clients can't logon

After upgrading the PDC from 2.2.7 to 3.0.0beta1, W2K clients
still work but the XP ones cannot log on to the domain any more.
The client pops up a message "The procedure is out of range",
and smbd logs

[2003/06/19 18:21:22, 0] ../rpc_server/srv_pipe.c:(1339)
  Invalid auth info 68 or level 5 on schannel
[2003/06/19 18:21:22, 0] ../rpc_server/srv_pipe_hnd.c:(605)
  process_request_pdu: failed to do schannel processing.

Registry settings (SignOrSeal etc.) are probably not the issue
as the XP clients work with Samba 2.2.7 (to which I have to
downgrade now).  Anybody seen this?


Also, all clients log

[2003/06/19 18:21:14, 0] ../passdb/pdb_smbpasswd.c:(416)
  getsmbfilepwent: malformed password entry (no terminating :)

but the Win2K ones apparently do not mind as they work.  The
smbpasswd file seems to be OK by visual inspection, what can
this be?

    Ciao, Lobo