Bitfields Problem

[Darwinist]

I created a bit 'bitfield_product.xml' file with the following:

<?xml version="1.0" encoding="ISO-8859-1"?>
<bitfields product="productname">
	<bitfielddefs>
		<group name="ugp">
			<group name="productpermissions">
				<bitfield intperm="true" name="limit" group="product_permissions" phrase="product_limit"></bitfield>
				<bitfield name="canview" group="product_permissions" phrase="product_canview">1</bitfield>
				<bitfield name="canupload" group="product_permissions" phrase="product_canupload">2</bitfield>
				<bitfield name="canedit" group="product_permissions" phrase="product_canedit">4</bitfield>
			</group>
		</group>
	</bitfielddefs>
</bitfields>

Everything works fine... settings are saved just fine when editing the usergroups via the admincp. However, when I use 'print_r($permissions)' in a PHP script, I get:

Array
(
[usergroupid] => 6
...snip...
[productpermissions] => 7
[limit] => 0
)

... the integer 'limit' is not displayed. When I use 'print_r($vbulletin->usergroupcache[6])' in a PHP script, I get:

Array
(
[usergroupid] => 6
...snip...
[productpermissions] => 7
[limit] => 2048
)

Why do the permission bitfields work, but not the integer?

Thanks for any help.