Please also post the full details/view of both old and new certificates.
But unless some date is wrong somewhere in these certificates (really unlikely with Google), or that there was an overlap between both certificates (old terminating after start-date of new), I would say that this is a bug in CertPatrol with too-new certificates.
You might try using the CertPatrol webchat to ask about this problem.
Examining the two posted certificates, I can see that both certificates are valid for now. The difference between the two is that one is issued to
*.google.com (google itself) and the other to
*.googleadservices.com (google advertising). Both were issued by the same authority (CA).
Google is therefore mixing content on the page from two domains, each domain having its own certificate. This is exactly what CertPatrol is supposed to warn about,
although the message text you see is incorrect and misleading.
I quote from their website :
Several websites have the bad habit of using multiple certificates for
the same hostname. We consider it a configuration error on their side,
but since they insist, you now have a little option of the certificate
change pop-up to accept any certificate for that host as long as the
issuer, that is the next higher level authority, stays the same.
The above shows that in the case of multiple certificates you will get a pop-up.
Which is exactly what is happening.
I would suggest that you accept both certificates without any worry.
You could signal this problem with the wording of this dialog to the developers via CertPatrol webchat.