[horde] PEAR.php required?

[Ali]

Hi everyone

I am a total newbie to horde and excited by the prospects of using IMP web
mail.

I have space on a shared UNIX server and have just set up a MySQL db on
there.  I have followed the config and install docs as far as possible but I
get a blank test.php and when I go to my horde folder via a browser I get

Fatal error: Failed opening required 'PEAR.php' (include_path='') in
/home/m/o/monsterfeet/public_html/horde/lib/Registry.php on line 4

I am accustomed to such messages in my own programming efforts but is there
something I am missing here? I have searched the docs for PEAR.php and found
no ref to it. Any advice to get me off the starting block would be much
appreciated.

Thanks

Ali