Active Error

in Subscribers

Active error:
Warning: Missing argument 2 for wpdb::prepare(), called in /home/sites/aametisa.com.br/web/site/wp-content/plugins/sendpress/sendpress.php on line 964 and defined in /home/sites/aametisa.com.br/web/site/wp-includes/wp-db.php on line 990 0

give me help

http://wordpress.org/extend/plugins/sendpress/