error using Get-TSServers (part of PSTerminalServices module)

I am using the custom module, PSTerminalServices found here (http://archive.msdn.microsoft.com/PSTerminalServices) but when I try to use the cmdlet Get-TSServers, whether I specify a domain name or not, I get the following error:

Exception calling "GetServers" with "1" argument(s): "The format of the specified domain name is invalid"
At C:\Windows\system32\WindowsPowerShell\v1.0\Modules\psterminalservices\PSTerminalServices.psm1:line:1376 char:24+ 		$TSManager.GetServers( <<<< $DomainName)

I checked the PSTerminalServices.psml file, and that block of code (for the Get-TSServers ) is below.

function Get-TSServers
{<#
	.SYNOPSIS
		Enumerates all terminal servers in a given domain. 
	.DESCRIPTION
		Enumerates all terminal servers in a given domain.
	.PARAMETER ComputerName
	    	The name of the terminal server computer. The default is the local computer. Default value is the local computer (localhost).
	.PARAMETER DomainName 	
		The name of the domain. The default is the caller domain name ($env:USERDOMAIN).
	.EXAMPLE
		Get-TSDomainServers
		Description
		-----------
		Get a list of all terminal servers of the caller default domain.		 
	.OUTPUTS
	.COMPONENT
		TerminalServer
	.NOTES
		Author: Shay Levy
		Blog  : http://blogs.microsoft.co.il/blogs/ScriptFanatic/
	.LINK
		http://code.msdn.microsoft.com/PSTerminalServices
	.LINK
		http://code.google.com/p/cassia/
	.LINK
		Get-TSSession
	#>
	[OutputType('System.Management.Automation.PSCustomObject')]
	[CmdletBinding()]
	Param(	
		[Parameter(
			Position=0,
			ParameterSetName='Name'
		)]		
		[System.String]$DomainName=$env:USERDOMAIN
	)
	try
	{
		$FuncName = $MyInvocation.MyCommand
		if(!$ComputerName)
		{
			Write-Verbose "[$funcName] ComputerName is not defined, loading global value '$script:Server'."
			$ComputerName = Get-TSGlobalServerName
		}
		else
		{
			$ComputerName = Set-TSGlobalServerName -ComputerName $ComputerName 
		}
		Write-Verbose "[$funcName] Enumerating terminal servers for '$DomainName' domain."
		Write-Warning 'Depending on your environment the command may take a while to complete.'
		$TSManager = New-Object Cassia.TerminalServicesManager
		$TSManager.GetServers($DomainName)
	}
	catch
	{
		Throw
	}
}

Any help would be appreciated, thank you!