Rewriting header incorrectly?

[Daniel Norton]

I'm not sure how spamass-milter could be doing this, but when I run the message directly through the spamassassin command line, it doesn't show the problem.

What I'm seeing is that in a spam report, the attached copy of the  spam has a "Received" header line rewritten incorrectly, as shown below. The rewritten line removes the "for" clause and the semi-colon that followed it. The semi-colon is mandatory, per RFC2821 (Sec. 4.4).

Any clues?

ORIGINAL:

Received: from mail-fx0-f215.google.com (mail-fx0-f215.google.com
[209.85.220.215])
    by smtp2.weirdmasters.net (8.14.3/8.14.3/weird) with ESMTP id
nB1GZE6Q028188
    for <address@hidden>; Tue, 1 Dec 2009 16:35:16 GMT

REWRITTEN INCORRECTLY:

Received: from mail-fx0-f215.google.com (mail-fx0-f215.google.com
[209.85.220.215])
    by smtp2.weirdmasters.net(8.13.0/8.13.0) with SMTP id nB1GZE6Q028188
    Tue, 01 Dec 2009 16:35:16 +0000
    (envelope-from <address@hidden>