If some network adapters on a server cluster are NOT registered by dynamic DNS, check the following:
1. Adapters that are used for the private interconnect between nodes should NOT have a default gateway address configured.
2. Insure that the DNS server is configured for dynamic updates.
3. Make sure that the adapter that corresponds to the network name resource has a DNS address, and that the option Register this connection's addresses in DNS is selected.
NOTE: In Microsoft Windows NT 4.0, DNS addresses are specified only once for TCP/IP. In Windows 2000, DNS addresses are specified for each network adapter.