[horde] Horde 4 Horde_Registry problem

[Eric]

 Installed Horde 4 following the instructions in the Readme and I get
  this error in my httpd error log:
  [Mon Apr 11 20:57:01 2011] [error] [client 10.1.10.40] PHP Warning:
  set_error_handler() expects the argument (Horde::errorHandler) to be a
  valid callback in /var/www/webmail/horde4/lib/core.php on line 53
  [Mon Apr 11 20:57:01 2011] [error] [client 10.1.10.40] PHP Fatal 
 error:
   Class 'Horde_Registry' not found in /var/www/webmail/horde4/index.php
  on line 14


  Ideas?