Assign Static IP fails for existing VM

Hi there,

I am working my way throught the Article for Setting up an Active Directory Forest on Azure as described here:
http://azure.microsoft.com/en-us/documentation/articles/active-directory-new-forest-virtual-machine/#createvm

Unfortunately when I come to Step 3 to assign the static IP as described in the article:
http://msdn.microsoft.com/library/azure/dn630228.aspx

When I try to execute the Step "Specify a static internal IP for a previously created VM" for example:

Get-AzureVM -ServiceName StaticDemo -Name VM2 | Set-AzureStaticVNetIP -IPAddress 192.168.4.7 | Update-AzureVM

I receive the following error:

Update-AzureVM : BadRequest: The value for parameter 'SubnetNames' is null or empty.

If I add the Command " ... | Set-AzureSubnet -SubnetNames Subnet | ...
I receive the following error and get stuck:

Update-AzureVM : BadRequest: The virtual network name cannot be null or empty.

What am I missing? I am simply following the instructions given by the help article.
Any help would be appreciated.