It would take some doing to be able to pull one of the hosts from vCenter. I might be able to tackle that tomorrow morning. I'm not sure if I mentioned it earlier, but this error appears on all the hosts in our vCenter.
The hosts are all Cisco UCS systems. 9 of them are B200M3 blades and 3 are C220 rack servers. I believe that they were installed from the Cisco OEM ESXi 5.1 ISO rather than the VMware ISO.