Disabling core extensions not working

Question

I have followed the answer in this question however when I test my results are coming back the the extensions are still enabled

I have created a file in app/etc/modules called zzz_Disabled_Modules.xml

<?xml version="1.0"?>
    <config>
        <modules>
            <Mage_Downloadable>
                <active>false</active>
            </Mage_Downloadable>
            <Mage_Authorizenet>
                <active>false</active>
            </Mage_Authorizenet>
            <Mage_Rss>
                <active>false</active>
            </Mage_Rss>
            <Mage_Poll>
                <active>false</active>
            </Mage_Poll>
            <Phoenix_Moneybookers>
                <active>false</active>
            </Phoenix_Moneybookers>
            <Mage_Bundle>
                <active>false</active>
            </Mage_Bundle>
            <Mage_Rating>
                <active>false</active>
            </Mage_Rating>
            <Mage_Tag>
                <active>false</active>
            </Mage_Tag>
            <Mage_Captcha>
                <active>false</active>
            </Mage_Captcha>
        </modules>
    </config>

I then have a file in my doc root called test.php

include('app/Mage.php');
Mage::app()->setCurrentStore(Mage_Core_Model_App::ADMIN_STORE_ID);
error_reporting(E_ALL | E_STRICT);
Mage::setIsDeveloperMode(true);
ini_set('display_errors', 1);

zend_debug::dump(Mage::helper('core')->isModuleEnabled('Mage_Poll'));
exit;

The result that comes back for all modules is bool(true)

Answer 1

Use a capital "Z" for the file name: ZZZ_Disabled_Modules.xml and don't forget to clean the config cache.