[sork] passwd 5.0.1 blank page "no preferences" problem

[Peter Borg (Horde)]

Hi,

Ubuntu 12.04.3 LTS
PHP 5.3.10-1ubuntu3.9
Horde Groupware webmail edition 5.1.3
SQL auth with custom queries
Passwd 5.0.1

Horde has been running for some weeks with no issues (and continues to 
do so).

Today I decided to try out the passwd module. Installed as per 
instructions using pear, installs with no errors, test script says 
everything's fine.

However, when visiting the page to set the password 
(services/prefs.php?app=passwd) the main content area of the page below 
the header is empty, showing just the usual Horde menu bar with the date 
below, and the title "Preferences for Password" below that along with 
the "Edit Preferences For" dropdown to the right. Additionally, an info 
popup appears with the text "There are no preferences available for this 
application." in the bottom-right.

There are no errors of any kind in any log, and in all other aspects 
Horde continues to run as expected.

There is no passwd/config/prefs.php file but then there isn't one in GIT 
and I can't see that one is required given the contents of 
passwd/lib/Basic.php

I'm sure I'm missing something obvious, all pointers gratefully received!