[syslog-ng]Log formatting

[syslog-ng@lists.balabit.hu]

Why is it that syslog-ng places the program name in the message string? As
in:

[CODE]
source shell {
        unix-dgram("/dev/log");
        internal();
        udp();
};
destination deadman {
        file("/var/log/deadman"
        template ("PROGRAM:$PROGRAM <MESSAGE:$MSG> LEVEL:$LEVEL
PRIORITY:$PRIORITY FACILITY:$FACILITY\n")
        template_escape(no)
);
};
log {
        source(shell);
        destination(deadman);
};
[/CODE]


[OUTPUT]

PROGRAM:roberto <MESSAGE:roberto: this is a test> LEVEL:notice
PRIORITY:notice FACILITY:user

[/OUTPUT]

I'd like to see just the words "this is a test" in the $MSG variable.
I am using syslog-ng version 1.5.24, on OpenBSD 3.5.

Thanks in advanced.