[imp] favourite recipients?

[liamr at umich.edu]

I'm trying to enable the favourite recipients addressbook.  I'm using 
Horde 3.2 RC 3, IMP 4.2 RC3, and Turba 2.2 RC3.  I've got "favourites" 
defined in turba/sources.php.  I've created the imp_sentmail table, and 
it's collecting data...  but I don't see "favourites" as an addressbook 
possibility in my prefs.
I don't have a personal search_sources preference, or search_fields defined.

Suggestions?
Liam