[imp] cannot log in directly into IMP unless a HORDE administrator

[Gerardo Red UNPA]

Hello. I want to configure IMP to allow me to log in directly. I have IMP set up to log in using the IMAP logon. 
Unfortunately, if I have HORDE set to use IMP for login, it tries to redirect me with no success complaining about cookies. If I have HORDE set up to use mysql to log in, it logs me in only if my user is listed as an administrator in conf.php. Either way, The user must be in IMAP and the admins list in horde's conf.php in order to allow me to log into IMP.

Since I have the mailing list turned on for "digest" I will try to put as much info about my config as possible.

in .../horde/config
servers.local.php
'hordeauth' => 'full'

conf.php:
$conf['auth']['admins'] = array('user1 at domain.com', 'user2 at domain.com');
$conf['auth']['params']['app'] = 'imp';
$conf['auth']['driver'] = 'application';
$conf['spell']['params']['path'] = '/usr/bin/aspell';
$conf['spell']['driver'] = 'aspell';

registry.local.php:
<?php
$this->applications['horde'] = array(
    'fileroot' => dirname(__FILE__) . '/..',
    'webroot' => '/webmail',
    'initial_page' => 'login.php',
    'name' => _("Portal de Correo Institucional UNPA"),
    'allow_guests' => true,
    'show' => true,
    'templates' => dirname(__FILE__) . '/../templates',
    'cookie_domain' => $GLOBALS['HTTP_SERVER_VARS']['domain.com'],
    'cookie_path' => '/webmail',
    //'server_name' => $GLOBALS['HTTP_SERVER_VARS']['SERVER_NAME'],
    //'server_port' => $GLOBALS['HTTP_SERVER_VARS']['SERVER_PORT']
);

in .../horde/imp/config
backends.php:
$servers['imap'] = array(
    // ENABLED by default
    'disabled' => false,
    'name' => 'IMAP Server',
    'hostspec' => 'localhost',
    'hordeauth' => true,
    'protocol' => 'imap',
    'port' => 143,
    // Plaintext logins are disabled by default on IMAP servers (see RFC 3501
    // [6.2.3])
    'secure' => 'tls',
    'maildomain' => 'dominio.com',
    // 'smtphost' => 'smtp.example.com',
    // 'smtpport' => 25,
    'cache' => false,
);

One other thing, since I could not get HORDE to create users on my dovecot/mysql configuration, I modified dovecot so that it used the horde horde_users table for authentication.  It seems to work well on the users I have tested, but then again, only as long as they are in conf.php listed as admins.

If you need more information I will provide it. 

Thanks in advance for your help and pointers.

Gerardo Contreras
Universidad Del Papaloapan
Departamento de Redes