Comments box acting as a search box

Hi, It seems when I add a comment to any of the comment boxes either WordPress or the theme is seeing this as a search request. You can see it here by adding any comment to the box https://testsite.theparamountexpress.com/2012/05/03/lorca-castle-hold-third-medieval-market/
You get this response:
“The page you requested could not be found. Try refining your search, or use the navigation above to locate the post”.

Has anyone else come across this or knows how to fix it?

Thanks
Keith