We received a report from a reader (thanks Marco!) that earlier today, "usertrust.com", a domain used by Comodo CA, apparently was pointing elsewhere for a while.  From information captured by passive DNS sensors, it indeed looks like the NS records were changed to "ns1.pendingrenewaldeletion.com" and the A records were changed to point to 208.91.197.132, both indicative of a domain that has been "parked" by Network Solutions. Two hours later, the DNS records were updated again, and pointed back to Comodo.  Given that the registration record on Network Solutions' WHOIS shows a renewal date of December 5 for the usertrust.com domain, it is probably fair to assume that "something" went wrong in the renewal.