title: Firefox: certificate is not trusted because the issuer certificate is unknown
body: <p>I'm working in a lab environment. I have a Windows-based CA and an SSL-secured website on IIS (on the same machine) with a cert issues from that CA.</p>
  
  <p>When I browse to this site in Firefox using SSL, I get an error "The certificate is not trusted because the issuer certificate is unknown."</p>
  
  <p>If I go to Tools -> Options -> Advanced -> Certificates -> View Certificates -> Authorities, my CA's cert is in the list. If I double-click that certificate, I get "Could not verify this certificate because the issuer is unknown."</p>
  
  <p>Isn't the whole point of adding a CA's cert into the Authorities list to tell Firefox, "Hey... you know this CA, go ahead and trust the certs that it issues?"</p>
  
  <p>How do I fix this problem?</p>