Add Interface to a Server but not to the cluster

Hi

I'm setting up a Cluster under VM Ware Workstation, just for Training.

With 2 Interfaces (one for cluster interconnect and one for domain) everything runs fine.  None of this Interfaces are connected to Internet, however.
When I add a 3rd Interface (which is NAT on VMWare) it becomes a clusterresource automaticly. I can't find a way to remove it from cluster controll. This a unwanted, as it should be a NIC that is used by the physical server only (for Updates, Servicepacks, etc).

Is this caused by VMWare or normal behavior in a clusterd system?

Thanks

Christian

Edit:
I just learned that this is "by design" in 2008 Clustering. Hoewer, is there a way to remove the NIC from Cluster Controll?