I installed the latest version of this patch in the latest version of ESX 5.1, it worked great and allowed me to spin up a Mac OS virtual machine in my ESX environment. After I installed it, I am unable to vMotion any virtual machines to this host. To test, I uninstalled it and vMotion began to work. My goal is to patch one host at a time without occurring any downtime to the virtual machines. This occurred when my hosts were on different versions. I upgraded all hosts to the latest and greatest for 5.1 and I still encounter the same issue. I can vMotion a few servers to this host with the unlocker installed, but after that vMotion breaks. The error I get is Operation timed out. It gets to 14%, Migrating active state of virtual machine. I am running VMware ESX Enterprise Plus 5.1.1157734. Any ideas why vMotion stops working with this patch installed?