samba - Aug 2002 - slow write speed

I have a 100mbps LAN. I'm writing a 9MB file from Windows XP to Debian
(testing) with Samba 2.2.3a. The write speed is about 1MB/s. Transferring
the same file over FTP is 5MB/s. Reading the same file over Samba is 3MB/s.

Looks like something is wrong with Samba. I've read a lot about Samba
optimization. I played with SO_SNDBUF. I've tried 4096, 8760, 8192. No
improvement.

Please help. Here's my current 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=4096
SO_RCVBUF=8192
        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\spassword:* %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

[download]
        path = /download
        writable = yes
        force directory mode = 775
        create mode = 675
        force create mode = 675
        directory mode = 775
        force group = win
        valid users = win
        guest account = win
        public = yes