[Samba] Samba 4 vs Samba 3

[Benjamin Huntsman]

So, I have "working" builds of Samba 3.6.10, and 4.0.2 using the traditional build system on AIX, both built with XLC.
For historical reasons, we're needing to use 'encrypt passwords = no', so that Samba uses the OS password.  

The odd thing, is, the 3.6.10 Samba works just fine, but the 4.0.2 doesn't allow connections.  Here's the Samba config I'm using on both:


Samba 3:
[global]
        encrypt passwords = No
        log level = 3
        os level = 8
        local master = No
        domain master = No
        idmap config * : range =
        idmap config * : backend = tdb

[testshare]
       path = /testshare
       read only = no

Samba 4:
[global]
        encrypt passwords = No
        log level = 3
        client max protocol = SMB2
        client min protocol = SMB2
        os level = 8
        local master = No
        domain master = No
        idmap config * : range =
        idmap config * : backend = tdb

[testshare]
       path = /testshare
       read only = no


On both a test Windows XP and Windows 7 machine, I have the unencrypted passwords policy enabled.  When running Samba 3.6.10 using the config above, I can map the share just fine.  However, under 4.0.x (I've tried 4.0.0, 4.0.1, and 4.0.2), when mapping the share on Windows, the password prompt comes back immediately, and I get the following in the log:


[2013/02/01 09:34:56.256107,  3] auth/auth.c:177(auth_check_ntlm_password)
  check_ntlm_password:  Checking password for unmapped user [10.33.72.67]\[root]@[SAMBATEST] with the new password interface
[2013/02/01 09:34:56.256176,  3] auth/auth.c:180(auth_check_ntlm_password)
  check_ntlm_password:  mapped user is: [SYSTST]\[root]@[SAMBATEST]
[2013/02/01 09:34:56.256843,  2] auth/auth.c:288(auth_check_ntlm_password)
  check_ntlm_password:  Authentication for user [root] -> [root] FAILED with error NT_STATUS_LOGON_FAILURE
[2013/02/01 09:34:56.256951,  2] ../auth/gensec/spnego.c:745(gensec_spnego_server_negTokenTarg)
  SPNEGO login failed: NT_STATUS_LOGON_FAILURE
[2013/02/01 09:34:56.259280,  2] smbd/smb2_server.c:3123(smbd_smb2_request_incoming)
  smbd_smb2_request_incoming: client read error NT_STATUS_CONNECTION_RESET


I am absolutely 100% certain that I'm typing the password correctly.  :)  Perhaps my build of Samba 4 is broken after all?  Anyone know why I'd see different behavior between 3.6.10 and 4.0.2, even though the config files are basically identical (though both were generated by swat)?
I really want to move to Samba 4 if I can...

Thanks!