Warnings on activation

Upon activation, these appear at the top of the page:

Warning: Missing argument 2 for wpdb::prepare(), called in /home/…/wp-content/plugins/podpress/podpress_upgrade_class.php on line 59 and defined in /home/…/wp-includes/wp-db.php on line 990

Warning: Missing argument 2 for wpdb::prepare(), called in /home/…/wp-content/plugins/podpress/podpress_upgrade_class.php on line 60 and defined in /home/…/wp-includes/wp-db.php on line 990

These also appear under System Information under podPress > General Settings.