A server certificate could not be validated

We have a deployed SELECTserver which has been running happily transmitting log until last night when we got this message.

Data Update Service - WARNING with status code 2 - service start time: 19/07/2013 12:00:42 AM - An error occurred retrieving the license from Bentley.com: - A server certificate could not be validated.

This happened once before and took a while to sort it out but it was found that the server needs a couple of SSL certificates that normally come via windows update. We do not have automatic windows server updates

This was fixed by importing two SSL certificates which were available on the bentley website for down loading at that time. Does anyone know where I can get these?