trouble installing root certificate

[John G. Heim]

I'm having trouble importing the root certificate for a certificate 
authority. I need to import the root cert for cacert.org. I've pointed 
safari at their web site, downloaded the root cert in pem format, and opened 
the cert. This runs the keychain admin program. I've imported the cert into 
the system keychain and it looks as if the cert is installed on my Mac. 
However, when I point safari to a server that uses a cert from cacert.org, 
it still says the cert is not from a trusted certificate authority.

Perhaps the Mac doesn't know the root cert is a root cert. But I cannot 
figure out how to get it to know that.

PS: Cacert.org is a non-profit organization that acts as a certificate 
authority. They issue certs via the web of trust model. Once you're in the 
web of trust, you can generate server certificates for free. You get into 
the web of trust by getting other members of the web of trust to verify your 
identity. So once you're in the web of trust, you can generate certificates 
in a matter of minutes at no cost.