Powershell Monitor not going past Initial Poll

I have a pretty simple Powershell script that isn't going past the initial poll but it tests out sucessfully, what could be the problem?

Monitor:

$WarningPreference = "SilentlyContinue"

$StrKey = "SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon"

$StrValueName = "WinStationsDisabled"

$strMachineName = "${Node.Caption}"

$objReg = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('LocalMachine', $strMachineName)

$objRegKey= $objReg.OpenSubKey($StrKey)

$strValue = $objRegKey.GetValue($StrValueName)

$strMsg="Statistic: " + $strValue

Write-Host $strMsg

exit 0