What are the differences between SSL Certificates?

What's the difference between a Trusted Root certificate and a Chained certificate?

A Trusted Root CA is a certificate of a certification authority (CA) which is added to a browser by the browser vendor. It signifies that the browser vendor (such as Microsoft) trusts the CA and will hence establish a high level of trust with websites that use SSL certificates signed by this CA.

A Chained (or Intermediate) root CA certificate is a certificate of a certification authority (CA) which is not present in a browser as opposed to a trusted root CA certificate. However, the chained certificate has been issued by a CA with a trusted root CA certificate. Since there is no direct relationship between the browser vendor and the chained root CA a lower level of trust is established. Furthermore authenticating sites with certificates signed by a chained root CA is more complex and requires more information to be exchanged between the server and the client.  

Does the R3000 support chained/intermediate certificates? 

When you purchase a Chained/Intermediate certificate, you will usually receive two separate certificates, both of which must be installed on the web server (i.e. the R3000).  Currently (as of August 2007), the GUI only allows you to upload a single certificate.   However, 8e6 Technical Support can install them for you from the back-end.