tinymce button is not working in version 3.5.1

i don’t know if this is a problem with the plugin or with wordpress 3.5.1. when i use visual editor, the button marked ‘registration form’ does nothing at all when i press it.

is there a way i can insert the form into text editor in html?

Thanks
amanda

http://wordpress.org/extend/plugins/simplr-registration-form/