regex header_checks and line wrapping

[J4K]

Good Monday morning to you all,

    I have a regex question for header_checks, that I cannot get to
work.  Possible caused by line wrapping.

I want to replace this line:
  Received:  from [127.0.0.1] (unknown [62.11.11.11]) (using TLSv1 with
cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate
requested) by klunky.co.uk (Postfix) with ESMTPSA id D34A4806B4 for
<test.t...@klunky.co.uk>; Mon, 14 Feb 2011 10:11:43 +0100 (CET)

with this line:
  Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost

I have the regex in header_checks, and its enabled in main.cf

header_checks = regexp:/etc/postfix/header_checks

# cat /etc/postfix/header_checks
/^Received: from \[[0-9.]+\]
 \([^) ]+ \[[0-9.]+\]\)
 \(using TLSv1 with cipher DHE-RSA-AES256-SHA \(256\/256 bits\)\)
 \(No client certificate requested\)
 by klunky.co.uk \(Postfix\)/ REPLACE /^Received: from [127.0.0.1]
(localhost [127.0.0.1]) by localhost/


I tried to simply drop the header for testing:
/^Received: from \[[0-9.]+\]
 \([^) ]+ \[[0-9.]+\]\)
 \(using TLSv1 with cipher DHE-RSA-AES256-SHA \(256\/256 bits\)\)
 \(No client certificate requested\)
 by klunky.co.uk \(Postfix\)/ IGNORE


In both cases, no change is made to the Emails.

Any ideas what was missed out?

Best regards.