Reply To: Database Error and/or both.php error……..

I see the problem, but you must had the problem even before 2.1.1
It’s like that since at least 1.8.

change /lib/function/front.php line 148+149 to

$wpdb->query( $wpdb->prepare("INSERT INTO ".$wpdb->prefix ."reservations(name, email, arrival, departure, room, number, childs, country, custom, customp, reservated, user )
VALUES (%s, %s, %s, %s, %d, %d, %d, %s, %s, %s, NOW() )", $val_name, $val_email, $val_fromdate_sql, $val_todate_sql, $val_room, $val_persons, $val_childs, $val_country, $val_custom, $val_customp, 0 ) );