Problems running antiword as an xinetd service

["Todd A. Jacobs" <codegnome.consulting+debian@gmail.com>]

I'm unable to get antiword to process standard input over a network
connection using xinetd. I've got the following in /etc/xinetd.d:

service antiword
{
        disable         = no
        type            = UNLISTED
        flags           += IPv4
        socket_type     = stream
        protocol        = tcp
        user            = nobody
        group           = nogroup
        wait            = no
        nice            = 10
        env             = PATH=/bin:/usr/bin ANTIWORDHOME=/usr/share/antiword
        port            = 2100
        server          = /usr/bin/antiword
        server_args     = -
        log_type        = FILE /tmp/antiword.log
        log_on_success  += PID EXIT DURATION
        log_on_failure  += HOST ATTEMPT
        banner_success  = /etc/motd
        only_from       = 127.0.0.0
}

However, attempting to write to the socket just gets me the MOTD:

exec 4<>/dev/tcp/127.0.0.1/2100
cat foo.doc >&4
cat <&4
exec 4>&-
exec 4<&-

Watching tcpdump, I can see that the Word document gets sent, but
antiword never reads standard input, as far as I can tell. I've also
tried putting antiword into a bash script, and calling that instead
from xinetd, but get the same results: no input from stdin.

Am I doing something wrong, or is there a bug in antiword?