The whole thing with browser-packaged trusted certificates is fundamentally wrong anyway.
YOU should be the person who decides who to trust, not some people who prepare the installation of your browser. Did you know that among trusted certificates are subjects like Sudan Telecom? Should you trust Sudan Telecom? Moreover, I have read a discussion among Firefox developers where a user asked about a specific certificate, and some dev replied: "Oh, it's one of AT&T's certificates", and someone from AT&T stepped in and said "No, this one has been revoked years ago". and then a lively discussion broke out about how the hell it got into their installation.
The point is - you SHOULD not trust this blindly, it's not something set in stone. For example, one of the servers I run generates similar message, because I did not want to pay someone I don't know just for a signature. Does it generate the error? Of course. Do I trust it? Hell yes, I set it up myself! So what do I do? I add it among the trusted ones, problem solved.
On the other hand, do I trust Sudan Telecom? No way!
You should THINK about which certificate you take as trusted and why.