Default Bitfield Permissions?

[Jaxel]

I have the following usergroup permissions file:

<?xml version="1.0" encoding="ISO-8859-1"?>

<bitfields product="medialibrary">
	<bitfielddefs>
		<group name="ugp">
			<group name="medialibperms">
				<bitfield group="medialibperms" name="canview" phrase="can_media_view" install="1,2,3,4,5,6,7">1</bitfield>
				<bitfield group="medialibperms" name="candeta" phrase="can_media_deta" install="1,2,3,4,5,6,7">2</bitfield>
				<bitfield group="medialibperms" name="cansubm" phrase="can_media_subm" install="2,5,6,7">4</bitfield>
				<bitfield group="medialibperms" name="cancomm" phrase="can_media_comm" install="2,5,6,7">8</bitfield>
				<bitfield group="medialibperms" name="canrate" phrase="can_media_rate" install="2,5,6,7">16</bitfield>
				<bitfield group="medialibperms" name="canrepo" phrase="can_media_repo" install="2,5,6,7">32</bitfield>
			</group>
			<group name="medialibmodperms">
				<bitfield group="medialibmodperms" name="canmodsubm" phrase="can_media_mod_subm" install="5,6,7">1</bitfield>
				<bitfield group="medialibmodperms" name="canmodcomm" phrase="can_media_mod_comm" install="5,6,7">2</bitfield>
				<bitfield group="medialibmodperms" name="canmoddeta" phrase="can_media_mod_deta" install="6">4</bitfield>
				<bitfield group="medialibmodperms" name="canmodtags" phrase="can_media_mod_tags" install="6">8</bitfield>
				<bitfield group="medialibmodperms" name="canmodcats" phrase="can_media_mod_cats" install="6">16</bitfield>
				<bitfield group="medialibmodperms" name="canmodhost" phrase="can_media_mod_host" install="6">32</bitfield>
			</group>
		</group>
	</bitfielddefs>
</bitfields>

			<installcode><![CDATA[
				require_once(DIR . '/includes/class_dbalter.php');
				$dbalter = new vB_Database_Alter_MySQL($db);

				echo('<ul>');
				echo('<li>Altering Table <strong>usergroup</strong> ...');
				vbflush();

				$dbalter->fetch_table_info('usergroup');
				$dbalter->add_field(array('name'=>'medialibperms','type'=>'INT','length'=>'10','attributes'=>'UNSIGNED','null'=>false,'default'=>'0'));
				$dbalter->add_field(array('name'=>'medialibmodperms','type'=>'INT','length'=>'10','attributes'=>'UNSIGNED','null'=>false,'default'=>'0'));

				echo('Done!</li>');
				echo('</ul>');
				vbflush();
			]]></installcode>

As you can see, I am using the "install=" parameter to give permission to certain usergroups by default. In VB3x, this worked fine for me. However, I have determined that this parameter is no longer functioning as intended. Now it appears that none of my usergroups are getting any permissions by default. What am I doing wrong for VB4x?