Can't save new custom checkout items

[JeffPyeBrook]

Get database error

[02-May-2014 10:35:34 UTC] WordPress database error Duplicate entry '' for key 'unique_name' for query INSERT INTO wp_wpsc_checkout_forms (name,type,active,mandatory,checkout_set,checkout_order,options) VALUES ('Sign me up!','checkbox','1','0',0,'10','a:1:{s:3:"Yes";s:3:"yes";}') made by require_once('H:\web-site-dev\acme.org\wp-admin\admin.php'), do_action('load-settings_page_wpsc-settings'), call_user_func_array, wpsc_load_settings_page, WPSC_Settings_Page::get_instance, WPSC_Settings_Page->__construct, WPSC_Settings_Page->set_current_tab, WPSC_Settings_Tab_Checkout->callback_submit_options