Two senders, and replies go to the wrong one

I have two pretty much identical installations in different servers. In one of them webform works as usual, like a dream. In the other one, when I get the mailed form there are two senders and one of them is the domain's postmaster, who has the main address of the installation. Replies go to that sender, not to the real one. What follows are the headers of both installations. I put them in the hope they are somehow useful.
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1) Installation that works fine.
In this case, the Return Path and the envelope are the
username-of-the-site@the server

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Return-Path:
Received: from cpanel47.gzo.com (cpanel47.gzo.com [67.19.34.210])

Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of academia@cpanel47.gzo.com designates 67.19.34.210 as permitted sender) smtp.mail=academia@cpanel47.gzo.com
Received: from academia by cpanel47.gzo.com with local (Exim 4.68)
(envelope-from )

To: lucho@thinkhispanic.com
Subject: Formulario de Consulta
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-transfer-encoding: 8Bit
From: lucho@cies.org.pe
X-Mailer: Drupal Webform (PHP/4.4.7)

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2) Installation that works wrong.
In this case, the Return Path and the envelope are the
General Settings e-mail address The Received: from is the server's username.
MIME-Version, Content Type and Transfer encoding are duplicated
Errors to:, Reply to: and the first From are again the GS e-mail
Php is different (5.2.5 vs. 4.4.7
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Return-Path:
Received: from creek.securenet-server.net (creek.securenet-server.net [207.45.187.114])

Authentication-Results: mx.google.com; spf=neutral (google.com: 207.45.187.114 is neither permitted nor denied by best guess record for domain of postmaster@ild.org.pe) smtp.mail=postmaster@ild.org.pe
Received: from cibertec by creek.securenet-server.net with local (Exim 4.68)
(envelope-from )

To: lucho@thinkhispanic.com
Subject: Prueba desde ILD
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-transfer-encoding: 8Bit
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8Bit
X-Mailer: Drupal
Errors-To: postmaster@ild.org.pe
Reply-To: postmaster@ild.org.pe
From: postmaster@ild.org.pe
From: lucho@cies.org.pe
X-Mailer: Drupal Webform (PHP/5.2.5)