[Exim] "non-printing character 27"

Guys, I'm having a little problem here,

2004-08-05 20:40:58 1BsgcE-0001Uv-Aa ** ar1@???
<test@???> F=<BLAH@???> R=reply T=auto_reply:
Expansion of "[Auto-Reply] $header_subject:" in auto_reply transport
contains non-printing character 27
2004-08-05 20:40:58 1BsgcE-0001Uv-Aa ** ar2@???
<test@???> F=<BLAH@???> R=reply T=auto_reply:
Expansion of "[Auto-Reply] $header_subject:" in auto_reply transport
contains non-printing character 27
2004-08-05 20:40:58 1BsgcE-0001Uz-Al <= <> R=1BsgcE-0001Uv-Aa U=vmail
P=local S=1600 from <> for BLAH@???
2004-08-05 20:40:58 1BsgcE-0001Uv-Aa Completed
2004-08-05 20:40:58 1BsgcE-0001Uz-Al => BLAH@??? F=<>
R=dnslookup T=remote_smtp S=1643 H=mfsmax.docomo.ne.jp
[203.138.181.240]
2004-08-05 20:40:58 1BsgcE-0001Uz-Al Completed

Here's the transport:

auto_reply:
driver = autoreply
subject = [Auto-Reply] $header_subject:
headers = "Content-Type: text/plain; charset=iso-2022-jp"
to = $sender_address
text = ${extract{mailReplyText}{$address_data}}
from = $local_part@$domain

Any reason why this shouldn't work?

If I send english subject emails to it, it works fine. Japanese emails
don't. Simple solution is to remove the $header_subject part, but I
wanted to keep that if possible.

Nathan.

--
Nathan Ollerenshaw - UNIX Systems Engineer
ValueCommerce - http://www.valuecommerce.ne.jp/