Hi Anthony,
the problem may very well lie in the CAS VM if you did not follow the configuration laid out in the links below. One question I do have; was the problem ever noticed before the updates you applied? Or is it just possible that migrations hadn't kicked in before? The symptoms you mention are very much inline with what would happen if a VM is not configured correctly for NLB in multicast mode, but you mentioned it's using unicast. Have you followed the steps in this link for unicast: http://kb.vmware.com/kb/1556
If you have the option to go multicast you would have better success while still maintaining vMotion compatibility.
http://kb.vmware.com/kb/1006525
http://kb.vmware.com/kb/1006558
-alex
