_ScreenCapture_CaptureWnd doesn't work for Games in fullscreen

[LeeTheMex]

_ScreenCapture_Capture doesn't work at all for games in fullscreen mode (just leaves a blank image) CaptureWnd Atleast has some of the image.
I can't get _ScreenCapture_CaptureWnd to work on Diablo 2: LOD Patch version 1.13 in fullscreen mode (it works fine in windowed mode). Images will have missing elements and some areas blacked out (attachment of image and user-created program given).

;Program created to test Screen Capture in Fullscreen mode game.
;Start script then open game in fullscreen mode. While in game,
;press Ctrl-Shift-R to take 11 screen captures and save to Test
;folder on dektop.

#include <Misc.au3>
#include <ScreenCapture.au3>


HotKeySet("^+r", "begin") ;Hotkeys: Ctrl + Shift + r    Runs program

While 1
	Sleep(250) ;must press Ctrl-Shift-r to start screen capture
WEnd

Func begin()
	Local $folder, $x
	$folder = @DesktopDir & "\Test" ;images create in Test folder on desktop
	DirCreate($folder)
	For $x = 0 To 10
		Sleep(100)
		_ScreenCapture_CaptureWnd($folder & "\" & String($x) & ".bmp", WinGetHandle("[ACTIVE]"))
	Next
EndFunc   ;==>begin