VB.Net: Reading NumLock status, even if the App doesn't have focus

Hi,
I need to read the NumLock status in VB.net.
After some Googling I found the following Class:
Public Class KeyState

  Declare Function GetKeyboardState Lib "user32" Alias "GetKeyboardState" (ByVal pbKeyState() As Byte) As Long
  Private KeyCode As Integer

  Public Sub New(ByVal keycode As Integer)
    Me.KeyCode = keycode
  End Sub

  Public Function KeyState() As Boolean
    Dim state(256) As Byte
    GetKeyboardState(state)
    Return (iif(state(Me.KeyCode) = 1, True, False))
  End Function

End Class

This works fine if the App has focus, but does not read the key correctly if another App as focus.

Is there a way to do this?

Thanks,

Richard