Hi Kevin I've fixed my issue:

1. Manually uninstall all SCOM agents on all nodes part of a cluster.

2. Remove the cluster name from agentless monitoring. If you can do it trough the SCOM console follow this article rickjury.blogspot.com/.../operations-manager-scom-2007-how-to.html

4. Delete the nodes from Agent Managed views in Administration pane.

3. Run Remove-DisabledMonitoringObject command in SCOM PowerShell. Wait 20-30 min.

4. Install SCOM agents on all nodes.

5. Add cluster name to Agentless monitoring.