If it's not a misconfiguration of your web browser, this problem most likely is based on proxy server(s) between your internet connection and Kemper's web server.
It could be a proxy server at your company (if you visit this site from work) or a proxy server of your ISP.
Could be solved easily if Kemper's web pages contained no-cache headers and/or no-cache meta-tags.
Cheers,
Martin