Safari version 5 on the Mac will not work with Blackboard

Before even getting to the login page in Blackboard, Safari 5 users may think Blackboard is down because they see this error message.  This has been verified only on Mac computers; PC's do not get this error.  Please have any students experiencing this problem use Firefox instead.

Here is Blackboard's list of compatible browsers:
http://kb.blackboard.com/pages/viewpage.action?pageId=56821440