[horde] Neglected _prefs_hooks

[Shaun Meyer]

Hi,

I've been unable to get a pair of hooks, _prefs_hook_username() and  
_prefs_hook_from_addr(), to execute in Horde 3.3 / imp 4.3.

I've gotten down to this:

horde/config/hooks.php:
if (!function_exists('_prefs_hook_from_addr')) {
     function _prefs_hook_from_addr($user = null)
     {
         return 'iRan at nowhere.com';
     }
}

horde/config/prefs.php:
$_prefs['from_addr'] = array(
     'value' => null,
     'locked' => true,
     'shared' => true,
     'type' => 'text',
     'hook' => true,
     'desc' =>  _("Your From: address:")
);

Surprisingly my from address isn't being set to 'iRan at nowhere.com' on login.

I have a test account whose preferences are cleared with the SQL  
statement, "DELETE FROM horde_prefs WHERE pref_uid = '(testaccount)';"  
and it hasn't had any better luck with it's own from_addr.

Why are my hooks being neglected?

Thanks in advance,

Shaun Meyer