[imp] Possible address book bug?

[Jacob Elder]

Horde 3.0.5, Imp 4.0.3, Turba 2.0.3

While viewing a message, clicking the address book icon next to an email
address produces the following error:

Failed to add an object: [8] "Strong(er) authentication required" DN: cn=Horde
Mailing List,ou=Users,dc=trec,dc=us (attributes: [a:4:{s:2:"cn";s:18:"Horde
Mailing
List";s:4:"mail";s:21:"horde at lists.horde.org";s:3:"uid";s:44:"20051016190012.1h8fztqzim4g at brewster.trec.us";s:11:"objectclass";a:4:{i:0;s:3:"top";i:1;s:6:"person";i:2;s:20:"organizationalPerson";i:3;s:13:"inetOrgPerson";}}]).Charset:ISO-8859-1

This message is clearly from the localldap source, which is being accessed with
limited privelages. However, when sending a message to a user not in either
address book, Imp is able to sucessfully update localsql.

$_prefs['add_source'] = array(
    'value' => 'localsql',
    'locked' => false,
    'shared' => true,
    'type' => 'implicit'
);

It looks like Imp (or Turba) is choosing the wrong address book source. Is this
a bug or do I have a configuration error somewhere?

-- 
Jacob Elder