Secure Websites and Firefox

Lately I've been getting a warning message (Website Certified by an Unknown Authority) every time I try to access a secure website like my webmail server using Firefox version 2.0.0.4. This did not use to happen before, and the certificates are valid. In IE7 same secure websites seem to behave just fine.

Any feedback on this would be appreciated.

Don't you get an option to add the item?

Try looking at <tools> <options> <advanced> <encryption>

You may have lost them when you updated?

Have a look at the certificate chain. Perhaps the certificate issuer is unknown and therefor the server's certificate cannot be verified.

Thank you for your replies :)