RegisterPowerSettingsNotification C# pinvoke

I am trying to detect when the laptop lid opens and closes, should be real simple. I can register that event properly it seems, but then I don't get notification when I close my laptop window.

Here's the DLL Import

(DLL code: http://www.pinvoke.net/default.aspx/user32/registerpowersettingnotification.html )(GUID_LIDCLOSE_ACTION: http://social.msdn.microsoft.com/Forums/en-US/tabletandtouch/thread/0bbf90be-9322-47fb-bfa4-016b57211b3a )

[DllImport(@"User32", SetLastError = true,   EntryPoint = "RegisterPowerSettingNotification",  CallingConvention = CallingConvention.StdCall)]private static extern IntPtr RegisterPowerSettingNotification(    IntPtr hRecipient,    ref Guid PowerSettingGuid,    Int32 Flags);static Guid GUID_LIDCLOSE_ACTION =    new Guid(0xBA3E0F4D, 0xB817, 0x4094, 0xA2, 0xD1,              0xD5, 0x63, 0x79, 0xE6, 0xA0, 0xF3);private const int WM_POWERBROADCAST = 0x0218;private const int DEVICE_NOTIFY_WINDOW_HANDLE = 0x00000000;const int PBT_POWERSETTINGCHANGE = 0x8013; // DPPE[StructLayout(LayoutKind.Sequential, Pack = 4)]internal struct POWERBROADCAST_SETTING{    public Guid PowerSetting;    public uint DataLength;    public byte Data;}

And then here is how I am registering the GUID_LIDCLOSE_ACTION event:

private void registerLidClosedNotification(){    IntPtr hWnd = this.Handle;    IntPtr ret = RegisterPowerSettingNotification(hWnd,                            ref GUID_LIDCLOSE_ACTION,                           DEVICE_NOTIFY_WINDOW_HANDLE);    Debug.WriteLine("Registered: "+ ret.ToString());    Debug.WriteLIne("LastError:"+ Marshal.GetLastWin32Error().ToString());}

Here's the output from that:

Registered: 6867560

LastError:0

Looks good to me.

Then where I'm supposed to recieve the message:

private static IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)        {            Debug.WriteLine("Entered: WndProc");  // we never make it even this far!

So why isn't it making it to the WndProc function if it is registered :[