Confirmation page displays incorrectly

After a visitor have RSVP yes the confirmation page shows RSVP:Yes and a Thank you! But then under that is the RSVP invitation and form again. It is very confusing to visitors. Is there some place I can remove the code? or what would you recommend. I have tried to re-install the plugin and have the last version installed. I have this plugin on three sites all with the same problem. Thank you!

http://sierrarosealpacas.com/grass-valley-alpaca-fiber-arts-festival/ – you can’t see the problem unless you RSVP

http://wordpress.org/extend/plugins/rsvpmaker/