Perhaps the page you are retrieving is compressed. Try out this code , i haven't checked it as i don't have internet access, but i hope it works. 
use strict;
use warnings;
use Compress::Zlib;
use WWW::Mechanize;
use WWW::Mechanize::FormFiller;

# Initialize a new oblect
my $mech = WWW::Mechanize->new();

# Fetch the given URL
my $url = "https://secure.secret.com/login/login.cfm?someParam=foo";
$mech->get($url);

# Throw error if page not found
$mech->success or die "Can't fetch the Requested page";

# Uncompress the page
my $dest = Compress::Zlib::memGunzip($mech->content);

# Initialize a new object to retrieve the form
my $f = WWW::Mechanize::FormFiller->new();
my $form = HTML::Form->parse($dest,$mech->base);

# Fill the form with login & password and submit
$f->fillout(user=>'xxx',password=>'xxx');
$f->fill_form($form);
my $request = $form->click();

# Fetch the next page
$mech->request($request);

# Uncompress the page
$dest = Compress::Zlib::memGunzip($mech->content);

# Retrieve the form & check for string
$form = HTML::Form->parse($dest,$mech->base);

print "$form\n";
exit 0;

[download]
I hope this works. Neeraj.

In reply to Re: HTTP::Headers error when submitting form via WWW::Mechanize by neeraj
in thread HTTP::Headers error when submitting form via WWW::Mechanize by jerrygarciuh

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