[Samba] WINS / port 445 question

[mrojava4 at eastgranby.k12.ct.us]

On one XP Pro client, I disabled WINS (removed the address of the WINS
server), so name resolution is done by broadcast.  In doing an ethernet
trace of this client's interaction with my samba server (3.0.2a), I
noticed that there was no traffic on port 445.  All data traffic was on
port 139.  Is this coincidence or does disabling WINS on the client force
netbios over TCP/IP?

My configuration is samba 3.0.2a configured as a PDC.  I am still using
smbpasswd.

My reason for doing this is that I am trying to get some understanding of
a "getpeername failed. Error was Transport endpoint is not connected"
which is happening all night long.  It is being logged only for our XP Pro
PC's.  We don't see it on our W98 PC's and don't have any W2000 PC's.