We are in the process of changing our OpenID keys. Unfortunately, the proper keys weren't rolled out quickly enough to all data centers due to a process issue. This means that if you start the OpenID flow in one data center, but end up completing it through another data center, your OpenID requests will fail.
We're in the process of sending traffic away from all the data centers with old keys, which will resolve this issue. Will update.
Thanks,
-Ryan