WordPress 3.5 Upgrade issues

So I now get this error message:

Warning: Missing argument 2 for wpdb::prepare(), called in /home/nowrehey/public_html/wp-content/plugins/download-code-redeemer/download-code-redeemer.php on line 170 and defined in /home/nowrehey/public_html/wp-includes/wp-db.php on line 990

Please help.

Thanks,
David

http://wordpress.org/extend/plugins/download-code-redeemer/