PEAR::DB Unknown Error

hello, i have programs a class with pear::db support, with the constructor i make the db connection. if I tie this class into another file and make a instance of the class with: require_once "db_handler.php"; $dbh = new db_handler(); i became the following mistake: DB::Factory failed: unknown error with the help of print_r($dbh); i became the output: d_handler Object ( [db] => db_error Object ( [error_message_prefix] => [error_prepend] => [error_append] => [mode] => 1 [level] => 1024 [code] => -1 [message] => DB Error: unknown error [debuginfo] => [callback] => ) ) What can be the reason for this problem ? best regards andre gildemeister