estepix on "[Plugin: Jetpack by WordPress.com] Comment IP addresses all show up as 127.0.0.1"

I have been struggling with this problem for quite some time until today I found this post:

http://ocaoimh.ie/2011/08/09/speed-up-wordpress-with-apache-and-varnish/

The solution proposed does not imply hacking the code:

Create a file called, for instance, /usr/share/php/real-ip.php with the following contents:

<?php
if ( isset( $_SERVER[ "HTTP_X_FORWARDED_FOR" ] ) ) {
        $_SERVER[ 'REMOTE_ADDR' ] = $_SERVER[ "HTTP_X_FORWARDED_FOR" ];
}
?>

Then add it to your php.ini file, search for:
auto_prepend_file =
And replace with:
auto_prepend_file = /usr/share/php/real-ip.php

It worked like a charm for me!