Smarty is supported only in PHP 4.0.6 or later. Smarty versions previous to 2.0 require the PEAR libraries. Be sure to include the path to the PEAR libraries in your php include_path. Config_file.class.php uses the PEAR library for its error handling routines. PEAR comes with the PHP distribution. Unix users check /usr/local/lib/php, windows users check C:/php/pear.