PHP warning in wp-admin

Hi there,

When I try and navigate to ~/wp-admin/themes.php?page=theme-settings I get the following error:

PHP Warning: Missing argument 2 for Secondary_HTML_Content_Input::setup_editor() in E:\Home\hkt2\Web\wordpress\wp-content\plugins\secondary-html-content\secondary-html-content.php on line 357

Hoping someone can help.

Thanks
Caroline

http://wordpress.org/extend/plugins/secondary-html-content/