[imp] blacklist / whitelist buttons are not hidden while disabled

[Nethub Online]

Hi all,

I disabled the blacklist in config/registry.local.php 

$this->applications['ingo']['provides'] = array('filter',
'mail/applyFilters', 'mail/canApplyFilters', 'mail/showFilters');

and in ingo/config/prefs.local.php
$_prefs['blacklist']['Locked'] = true;
$_prefs['whitelist']['Locked'] = true;

However the blacklist / whitelist buttons are still shown, is there anything
I missed?
http://photo.yeah.hk/albums/userpics/10012/imp_blacklist_whitelist.jpg

Nethub Online Limited
http://www.nethub.com.hk