[sork] Passwd and LDAP problems

[AJ]

Hi,
  I am using IMP for authentication against a cyrus imap server, which in turns
authenticate against an LDAP directory.
Mu uid's are in the form of firstname.lastname at domain.com.
I am NOT using realms with horde.  Passwd does not seem to work with or without
the realm setting in backends.php.  What do I need to do to get this to work?
I keep getting a user not found error.  It seems to be ignoring the @ sign.
Here is backends.php:

$backends['ldap'] = array(
    'name' => 'LDAP',
    'preferred' => 'localhost',
    'password policy' => array(
        'minLength' => 3,
        'maxLength' => 8
    ),
    'driver' => 'ldap',
    'params' => array(
        'host' => 'localhost',
        'port' => 389,
        'basedn' => 'ou=users,dc=domain,dc=com',
        'uid' => 'uid',
        'realm' => 'domain.com',
        'encryption' => 'ssha',
        'tls' => false // make sure the host == cn in the server certificate
    )
);


Thanks!
AJ