[horde] Unable to install trean

[Art]

I was trying to install trean (1.0-cvs) on working horde installation 
3.3.4. After download I was able to go to Admin/Setup and generate 
config, but after I log out and log back in, sidebar is gone and I can't 
access trean. I get following errors in the apache error_log:

PHP   1. {main}() /usr/share/horde/services/portal/sidebar.php:0, 
referer: http://192.168.254.100/horde/index.php
PHP   2. Horde_Block->buildTree() 
/usr/share/horde/services/portal/sidebar.php:228, referer: 
http://192.168.254.100/horde/index.php
PHP   3. Horde_Block_trean_tree_menu->_buildTree() 
/usr/share/horde/lib/Horde/Block.php:191, referer: 
http://192.168.254.100/horde/index.php
PHP   4. require_once() 
/usr/share/horde/trean/lib/Block/tree_menu.php:18, referer: 
http://192.168.254.100/horde/index.php

Can somebody please let me know if this is a bug I should file or a 
problem with a setup, and if problem with setup, how can I start 
debugging it.

Thanks to the horde team for great work!
and thanks in advance for the help,

art