Yeah, Java's phoning home to see if there's any updates available and getting that certificate. As I understand it (although there are people far more knowledgeable than me about this on c9), more than likely there's nothing actually wrong with the certificate itself, your computer just can't check with Comodo that they've not revoked the certificate.
or another possible case might be that something put a bad update location on your system and the software is going to a bad site with a fake SSL cert that looks like it's from them but not and some bad folks are betting that a lot of folks will assume the cert is real, trust it and get more malware installed.
I do not know if that is the case but ..... I would check to see if you can verify that the CA is not having a problem and does oracle / java use them for the certs and do they have any info about that problem happening to others.