samba - May 2002 - slow localhost smbclient xfer

I'm transferring a 1MB file over the "lo" interface on samba
2.2.3a-6
(debian woody) using smbclient.
The speed is 71 kb/s. Why is it so slow?

Here's the relevant part of my smb.conf:

[global]
        log level = 0
        syslog only = no
        passwd program = /usr/bin/passwd %u
        printing = cups
        dns proxy = no
        name resolve order = lmhosts host wins bcast
        encrypt passwords = true
        time server = yes
        socket options = TCP_NODELAY IPTOS_LOWDELAY SO_SNDBUF=8192
SO_RCVBUF=819
2
        short preserve case = yes
        bind interfaces only = yes
        printcap name = lpstat
        invalid users = root
        max log size = 1000
        obey pam restrictions = yes
        passwd chat = *Enter\snew\sUNIX\spassword:* %n\n
*Retype\snew\sUNIX\spas
sword:* %n\n
        security = share
        preserve case = yes
        unix password sync = false
        workgroup = WORKGROUP
        server string = %h server
        syslog = 0;
        netbios name = brain
        guest account = nobody
        username map = /etc/samba/user.map
        interfaces = 192.168.1.0/24 192.168.0.0/24 127.0.0.1