[Samba] huge number of port 139 messages in nmbd.log

[David Mathog]

Since upgrading to Samba 3.0.28a (from 3.0.24) the nmbd.log file has
been full of these:

[2008/09/04 09:53:43, 1] lib/util_sock.c:open_socket_out(888)
  timeout connecting to 131.215.96.55:139
[2008/09/04 09:53:43, 1] libsmb/cliconnect.c:cli_connect(1498)
  Error connecting to 131.215.96.55 (Operation already in progress)

>From a large assortment of machines in our campus net (131.215).  None
of these machines are under my control, but the majority of them are
DHCP addresses - which makes those at least likely to be Windows
workstations.

The firewall on my Samba server allows 139 access from the local net.
However, nmap to these machines has yet to show one with a 139 port
open, which would at least explain part of this message.

Anybody know what these messages are and how to get rid of them?  I
don't think there are any machines pre Win2000 that need to connect to
my server anymore.  Should I just close port 139? 

Thanks,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech