I had the same exact error going on in my server.log file. I could not get it to work just by deploying to IP address as you are able to do however. KB66747 fixed this for me. But the one last step not listed was that I had to add to the local admin group on the unmanaged node the domain service account which I am now using to start the three ePO services on my ePO server. In my case I'm trying to deploy 4.6.0 agents to W2K8 servers with 4.0 agents already on them which are being managed by a different/old ePO server.