DB Error

My DB line looks like: $rcmail_config['db_dsnw'] = 'mysql://user:pass@localhost/roundcube'; // sqlite example: 'sqlite://./sqlite.db?mode=0646';

// PEAR database DSN for read only operations (if empty write
database will be used) // userful for database replication $rcmail_config['db_dsnr'] = '';

And I get this error:

DB Error in /var/www/reflex8.com/roundcubemail/program/include/ rcube_db.inc (63): DB Error: not found

Fatal error: Call to undefined method DB_Error::query() in /var/www/ reflex8.com/roundcubemail/program/include/rcube_db.inc on line 119

Any ideas?