http://blogs.msdn.com/b/clustering/archive/2008/01/08/7024031.aspx?Redirected=true
In this article it states-
Since impersonation is used there are some functions which can only be called from the local node. Due to security reasons most domains only allow one impersonated connection. Since the remote connection is impersonating the security context from the previous connection, another remote connection cannot be made. When a remote connection is created, that becomes the one permitted impersonated connection. Therefore any additional remote connections are not allowed. This becomes an issue for some functions in the cluster WMI provider. This is not an issue for domains in which the administrator has turned on delegation.
Does anyone know what settings/configuration = "turned on delegation"