[imp] Nothing in options -> addressbooks

[Phil Dunn]

I've installed imp and turba and have the two working ok independently, 
the link between two switch between the two works fine also. However 
the problem is that there are no buttons in the compose window to help 
pick addresses, and also when I go options -> addressbooks I'm not 
shown any address books to choose.
I've done a reasonable amount of searching to try and fix this, but 
either my problem is slightly different from everyone else's or I'm 
missing something obvious.
Here are some of my configurations:

$_prefs['sourceselect'] = array('type' => 'special');

$_prefs['search_sources'] = array(
     'value' => "localsql\tpmldap",
     'locked' => false,
     'shared' => false,
     'type' => 'implicit'
);

$_prefs['search_fields'] = array(
     'value' => 'name',
     'locked' => false,
     'shared' => false,
     'type' => 'implicit'
);

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

And i've got thin in my conf.php $conf['menu']['apps'] = array('turba');

I assume everything in my sources.php is fine as I can access and make 
entriesimp at lists.horde.org.

Any help would be gratefully recieved.
Thanks
Phil