One of my customer had recently deployed Exchange 2010 and they had received the following error on EMC for certificate request

image

I did a search on BING and found some blogs that helped us resolve the issue. Sharing it on my blog if you are in a similar boat

 

http://blogs.technet.com/b/exchange/archive/2010/07/26/emc-and-certificates-with-failed-revocation-checks-in-exchange-2010.aspx

http://social.technet.microsoft.com/Forums/en-US/exchange2010/thread/299c8ebe-223c-43ab-8cbc-c8221991813a