[horde] Empty Siedepanel Horde 4.0-RC1

[Yves Bilgeri]

Installed Horde 4.0-RC1 with PEAR and separate PEAR installation 
directory. Everything went well so far. But now when I open the Horde 
URL, the sidepanel is just empty, no links in it. So I appended 
admin/config to the URL and could then setup the DB and an IMAP-Auth 
config. After that when I try to login, I get the error:

Fatal error: Class 'Horde_Imap_Client' not found in 
/var/www/horde4/pear/php/Horde/Auth/Imap.php on line 173


Any hints what I did wrong?

Thanks, Yves