Erro ao Reiniciar o Horde

Pessoal, estou tentando instalar um webmail, o Qmail, Corrier-IMAP, Horde, porem nao estou conseguindo. esta ocorrendo os sequintes erros:

Warning: main(PEAR.php): failed to open stream: No such file or directory in /usr/local/www/horde/lib/core.php on line 26

Warning: main(): Failed opening 'PEAR.php' for inclusion (include_path='/usr/local/www/horde/lib:.:') in /usr/local/www/horde/lib/core.php on line 26

Warning: main(Log.php): failed to open stream: No such file or directory in /usr/local/www/horde/lib/Horde.php on line 3

Warning: main(): Failed opening 'Log.php' for inclusion (include_path='/usr/local/www/horde/lib:.:') in /usr/local/www/horde/lib/Horde.php on line 3

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/www/horde/lib/core.php:26) in /usr/local/www/horde/lib/Test.php on line 96

Warning: Cannot modify header information - headers already sent by (output started at /usr/local/www/horde/lib/core.php:26) in /usr/local/www/horde/lib/Test.php on

Alguem tem uma ideia

Márcio Antunes