PEAR not installed correctly?

I have some trouble using PEAR, hope someone can help PEAR is located here: D:\server-xampp\sites\unipaix\trunk\www\libs\PEAR (the folder contains a PEAR.php file and a PEAR folder) I wanted to test the DB package then and copied DB into this folder: D:\server-xampp\sites\unipaix\trunk\www\libs\DB (the folder contains a DB.php file and a DB folder) Now, here is what I did: I inserted into my code the following line to adjust my include_path directive: ini_set("include_path", ini_get("include_path") . PATH_SEPARATOR . 'D:/server-xampp/sites/unipaix/trunk/www/libs/PEAR'); In my code I then called the DB class like this: // ... $db =& DB::connect($dsn, $options); if (PEAR::isError($db)) { die($db->getMessage()); } // ... $db->disconnect(); And here is the error I get: Fatal error: Call to undefined function: assertextension() in D:\server-xampp\xampp\php\pear\DB\mysql.php on line 115 (Notice that the path has changed. I don't think it's an error, but who knows) What went wrong here? Hope anyone can help... Nicolas