Windows NLB : Get-NLBClusterNode reports Invalid Data

Question

I've setup a cluster of 2 Nodes using Windows Network Load Balancing feature. Everything is well setup, my cluster

For moinitoring purposes, I'd like to get the status of the nodes within the cluster by using PowerShell. I've discovered this Nagios probe, based on the cmdlet Get-NLBClusterNodebut the PS cmdlet returns an error.

I've tried running it in an elevated PowerShell prompt, but I get the same behavior :

PS C:\Users\Administrator> Get-NlbClusterNode
Get-NlbClusterNode : Failed to perform operation. Please refer to the    cmdlet help to make sure all parameters are specified correctly.
At line:1 char:19
+ Get-NlbClusterNode <<<<
    + CategoryInfo          : InvalidData:(Microsoft.Netwo...tNlbClusterNode:GetNlbClusterNode) [Get-NlbClusterNode],
    Exception
    + FullyQualifiedErrorId : COMException,Microsoft.NetworkLoadBalancingClusters.PowerShell.GetNlbClusterNode

If I run the Get-NLBCluster cmdlet, I get the info on the cluster like this :

PS C:\Users\Administrator> Get-NlbCluster
Name               IPAddress           SubnetMask          Mode
----               ---------           ----------          ----
cluster-name         XX.XX.XX.XX         255.255.255.0       MULTICAST

In the cmdlet documentation, I've read that the -InputObject with the name of the cluster was mandatory. But even with that mentionned, I get another error (cannot biend parameter) :

PS C:\Users\Administrator> Get-NlbClusterNode -InputObject "cluster-name"
Get-NlbClusterNode : Cannot bind parameter 'InputObject'. Cannot convert the "gw-cluster" value of type "System.String"
    to type "Microsoft.NetworkLoadBalancingClusters.PowerShell.Cluster".
At line:1 char:32
+ Get-NlbClusterNode -InputObject <<<<  "cluster-name"
    + CategoryInfo          : InvalidArgument: (:) [Get-NlbClusterNode], ParameterBindingException
    + FullyQualifiedErrorId : CannotConvertArgumentNoMessage,Microsoft.NetworkLoadBalancingClusters.PowerShell.GetNlbClusterNode

The cmdlets of this module that works are :

• Get-NLBCLuster,
• Get-NLBCLusterDriverInfo.
• Get-NLBCLusterNodeInterface.My node has 2 network interfaces, but only tghe second is used for the NLB. The first one is for a management access
• Get-NLBCLusterPortRule
• Get-NLBCLusterVip

Those that don't work are :

• Get-NLBCLusterNode (obviously)
• Get-NLBCLusterNodeDip.

I'm running a Server 2008R2, with the .Net version 3.5.1.

Could anyone have a track on rhe cause of this issue ?