[ingo] New Rule button missing

[Mariusz Czyz]

Versions:
Horde 3.3.3
Imp 4.3.3
Ingo 1.2.1

The 'New Rule' button is missing on the Filters page. Also, when trying 
to edit an existing rule this error shows on top of the page: "You are 
not allowed to create or edit custom rules." I don't think it's a bug 
but rather misconfiguration. However, I've compared this test instance 
with our production one and I can't find the culprit.

backends.php
###########

$backends['sieve'] = array(
    'driver' => 'timsieved',
    'preferred' => '127.0.0.1',
    'hordeauth' => true,
    'params' => array(
        // Hostname of the timsieved server
        'hostspec' => '127.0.0.1',
        // Login type of the server
        'logintype' => 'PLAIN',
        // Enable/disable TLS encryption
        'usetls' => false,
        // Port number of the timsieved server
        'port' => 2000,
        // Name of the sieve script
        'scriptname' => 'ingo',
        // The following settings can be used to specify an administration
        // user to update all users' scripts. If you want to use an admin
        // user, you also need to disable 'hordeauth' above. You have to use
        // an admin user if you want to use shared rules.
        // 'username' => 'cyrus',
        // 'password' => '*****',
    ),
    'script' => 'sieve',
    'scriptparams' => array(),
    'shares' => false
);

#############