We recently switched from GoDaddy SSL certificate to Verisign's.
Installation on Nginx went well.

Some users and browsers are reporting that the "certificate was signed by an
unknown authority".

You can try this by going to https://www.spellingcity.com.

It doesn't seem that we had this issue with the GoDaddy certificate... is
there anything else I need to do with Nginx SSL configuration to make this
issue "go away" or is this strictly a Verisign issue (I am contacting them
as well).

Thanks