Frank,
It is probably due to the setup or security settings for your web browser. Your name, email address, new messages since your last visit are all stored on a "cookie" which is placed on your hard drive by this website. If your web browser is not set to accept cookies, or at least accept cookies from history-sites.com and history-sites.net, then when you return the information from your previous visit(s) is lost.
I hope that helps you.
Jim