Cannot unsubscribe (db_query error)

When I click to unsubscribe link on mail, I got these errors:

Table 'mydatabase.notifications' doesn't exist query: DELETE FROM notifications_queue WHERE sid = 1 in /var/www/my/path/to/drupal/includes/database.mysql.inc nella riga 172.

Table 'mydatabase.notifications_queue' doesn't exist query: DELETE FROM notifications_queue WHERE sid = 1 in /var/www/my/path/to/drupal/includes/database.mysql.inc nella riga 172.

Table 'mydatabase.notifications_fields' doesn't exist query: DELETE FROM notifications_fields WHERE sid = 1 in /var/www/my/path/drupal/includes/database.mysql.inc nella riga 172.

It seems that {$table} on db_query make some fuss on notifications.module, so I use {".$table."} and unsubscribe links works, with no error submitted to watchdog. Here's the patch.