Description of problem: Nmbd was attempting to put a lock file in /var/locks/.nmbd this directory doesn't exist. "ln /var/lock /var/locks -s" fixed the problem.
Can you please provide more information when that happens ? When I try to start nmbd on my fully updated f16 box, it just succeeds and does not try to access /var/locks directory at all. Can you try to start nmbd manually with -d10 so we see more output ? Thanks
[2012/05/18 00:34:50, 0] nmbd/nmbd.c:860(main) nmbd version 3.6.0rc2-69rc2.fc16 started. Copyright Andrew Tridgell and the Samba Team 1992-2011 [2012/05/18 00:34:50, 0] lib/util_sock.c:1322(create_pipe_sock) error creating socket directory /var/locks/.nmbd: No such file or directory This was generated in response to 'systemctl start smb.service' Now that I've ln'd /var/locks to /var/lock all is well
F16 provides already Samba 3.6.5 as an update. Please to the latest version.
Reopen if it still can be reproduced with the latest version.