The sitestream.twitter.com SSL certificate will be changing from the current VeriSign certificate to a DigiCert certificate within the next month.
You should have both sets of root certificates installed on machines which connect to Twitter’s APIs, but as a reminder, the root certificates are available from each vendor at:
Please see Connecting to Twitter API using SSL for more information about using SSL with Twitter’s APIs.
The current SSL Certificate for sitestream.twitter.com will expire on November 23, 2012. We expect to make this change before then, within the next 1 to 2 weeks. Please use this discussion thread to ask questions or leave feedback about this change.