I've a search page developed by using MS Frontpage

When a the search form is submitted on the server the following error page is displayed as response.

The returned page is http://mysite/MyWebs/_derived/nortbots.htm

FrontPage Run-Time Component Page

You have submitted a form or followed a link to a page that requires a web server and the FrontPage Server Extensions to function properly.

This form or other FrontPage component will work correctly if you publish this web to a web server that has the FrontPage Server Extensions installed.

Click the <Back> arrow to return to the previous page.

I know that the Frontpage extentions are installed on the web servers since on the same site some other Frontpage applications are running successfully.

Thanks for advices

Eralper