You should really open a support case for this, but here are a couple more things to check.
Are you using the hostname or IP for discovering the new node?
Do you have IPv6 enabled on your Orion server? You may want to disable this if you are not using it.
Go to this link on your Orion server and click on the appropriate "Fix Me" links (assuming you are running Win2K8):
http://support.microsoft.com/kb/929852