Why doesn't the GPC resolve "do" anymore for HTML form links in 3.7?

[Scuzzy]

I tried asking this question in the 3.7 troubleshooting section and was shot down for asking a programming question. Is this a bug or is this a new design feature for 3.7?

We use "do" in links in HTML forms on our site. This used to be able to be pulled via the GPC class in 3.6.8 and prior, in 3.7 it does not work:

Sample HTML:

<?php
/*======================================================================*\
|| #################################################################### ||
|| #################################################################### ||
\*======================================================================*/
// ####################### SET PHP ENVIRONMENT ###########################
error_reporting(E_ALL & ~E_NOTICE);
// #################### DEFINE IMPORTANT CONSTANTS #######################
define('THIS_SCRIPT', 'testsubmit');
// ################### PRE-CACHE TEMPLATES AND DATA ######################
// get special phrase groups
$phrasegroups = array('fronthelp');
// get special data templates from the datastore
$specialtemplates = array();
// pre-cache templates used by all actions
$globaltemplates = array(
 'test_template'
);
// pre-cache templates used by specific actions
$actiontemplates = array();
// ######################### REQUIRE BACK-END ############################
require_once('./global.php');
 
$vbulletin->input->clean_array_gpc('r', array(
 'do' => TYPE_NOHTML,
 'myaction' => TYPE_NOHTML
));
$ot_do=$vbulletin->GPC['do'];
$ot_myaction = $vbulletin->GPC['myaction'];
echo "Do: $ot_do<br>";
echo "Request Do: " . $_REQUEST['do'] . "<br>";
echo "MyAction: $ot_myaction";
eval('print_output("' . fetch_template('test_template') . '");');
?>

Sample Template:

<form action="testsubmit.php?myaction=myactionval&do=testdoval" method="post">
   <input maxlength=255 name=mytextval size=60>
   <input type="submit" class="button" name="sbutton" value="Send"/>
</form>