So I recently upgraded by VMware vCenter server from 4.0 U1 to 4.0 U2 and ran across a little problem. After I upgraded I couldn’t attach any hosts to the vCenter server. It kept telling me that vCenter couldn’t talk to the host even though it could.
After digging into the logs we saw that there was a problem with the SSL handshake. It turns out that another restart of the vCenter services was all that was needed to clear up the problem.
So if you are having problems attaching hosts to vCenter after your upgrade just restart the vCenter services on the vCenter server and you should be fine.