 <p>Make sure that your self-signed certificate matches your site URL. If it does not, you will continue to get a certificate error even after explicitly trusting the certificate in Internet Explorer 8 (I don't have Internet Explorer 7, but Firefox will trust the certificate regardless of a URL mismatch).</p> <p>If this is the problem, the red "Certificate Error" box in Internet Explorer 8 will show "Mismatched Address" as the error after you add your certificate. Also, "View Certificates" has an <strong>Issued to:</strong> label which shows what URL the certificate is valid against.</p>