A common complaint when visiting the Clark Blackboard site, is the warning screen some will see about the site’s security certificate.  The best solution for browsers which display this nag screen is to add an exception for Clark.Blackboard.com when prompted.  Clark’s Blackboard certificate is valid and good until 2011.  For those geeks who are extra wary, here is a handy tool for diagnosing incidents like this:

Check on Security Certificate

Type in https://clark.blackboard.com and click Check Site for a full report

Update: This issue has been resolved