Vista (& Mac OSX 10.4+) Client on Samba PDC Network
| 
Things to check to make sure your Vista client (and Mac OSX 10.4 client) can logon/connect to a Samba PDC (Linux) domain:Client (Vista) Side:
1. Run secpol.msc and under Local Settings, Security Policies, double-click "Network Security: LAN Manager authentication level" - Set this to "LM and NTLM – use NTLMV2 session security if negotiated".
-> N.B: If you change this remember to REBOOT.
Server (Samba PDC) Side:
1. Make sure the following exist in the global section of /etc/samba/smb.conf:
client ntlmv2 auth = yes (this, in fact, automatically sets client lm auth = no and client plaintext auth = no)
host msdfs = no (only needed for up to samba 3.0.25 apparently).
-> N.B. If you change/add these settings, remember to restart the smbd/nmbd daemons.
IMPORTANT UPDATE: This also allows MAC OSX 10.4 (Tiger) clients to connect as well.
2. The [profiles] share directory (toplevel) needs to be writable by all users who will be storing roaming profiles there (it's NOT enough to have each users directory writable by themselves only - they need to be able to write to the level above)
Remember to check any older clients (XP, etc) after changing the server settings to make sure they can still logon to your domain!