Shell.Explorer.2-Object and cancel Navigation with BeforeNavigate2 fails

[card0384@…]

; Test script to embed an Shell.Explorer.2 (MS WebBrowser) control into an AutoIt GUI
;
; Reference for the BeforeNavigate2 event under: ​http://msdn.microsoft.com/en-us/library/aa768326(VS.85).aspx
;
; Error description:
; In order to have the full functionallity of the BeforeNavigate2 event it is needed to have the $IECancel paramter read and writeable. This parameter
; is documented as read and writeable but it is nowwhere documented how this is done in AutoIt. So I've tried to the ByRef keyword and this causes a
; crash of AutoIt. The Code below will reproduce this crash and when the ByRef keyword is removed then the code will work but there is still no possibillity
; to cancel the navigation.

#include <GUIConstants.au3> ; Begin of the main code
$oIE = ObjCreate ("Shell.Explorer.2") ; create Shell.Explorer.2 object
$GUI = GUICreate ("Embedded IE-Webbrowser", 830, 500, -1, -1 ) ; Create a simple GUI
GUISetState()
$GUIIE = GUICtrlCreateObj ($oIE, 1, 1 , 829 , 499) ; embed Shell.Explorer.2 object in GUI
$oIEEvents = ObjEvent ($oIE,"IEEvent","DWebBrowserEvents2") ; Assign events to functions starting with IEEvent
$oIE.navigate ("www.microsoft.com") ; navigate to www.microsoft.com
While $oIE.busy

Sleep (30) ; Idle around while site is loading

Wend

Sleep (5000) ; Sleep vor 5 seconds and then ...
Exit ; ... exit
; End of the main code

; Event: Will be called before a navigation starts
Func IEEventBeforeNavigate2 ($IEpDisp, $IEURL, $IEFlags, $IETargetFrameName, $IEPostData, $IEHeaders, ByRef $IECancel) ; Remove ByRef and it will work

$IECancel = True ; Dummy - Until I add other code

EndFunc