[horde] problem with admin users

[Shannon Reall]

We recently upgraded to horde 3.0.7 and imp 4.0.4.  During the set-up I
listed 3 users in the administrator list in the 'Authentication' tab of the
Horde setup.  This worked fine when they logged in.  I then configured imp
and went back and changed the backend Horde should use for authentication
to: Let a Horde application handle authentication.  Now when these users
login they no longer see the Administration menu.  Have I configured
something incorrectly?  When I look at conf.php they are still listed:
$conf['auth']['admins'] = array('ser', 'tvd', 'emm');

Shannon