EVENT_MOUSEUP ... Canvas

I try to make a "PopupWindowMenu" when right clicking the window, but if I use a GraphicsCanvas, MouseEvents are locked on the canvas, and I can't get events anymore from panels.

Local win:TGadget=CreateWindow("MouseTest",5,5,800,600)
Local gad:TGadget=CreatePanel(5,5,790,520,win)

can:TGadget		=	CreateCanvas(5,80,780,400,gad)

popup:TGadget=	CreateMenu("coucou",0,Null)
				CreateMenu("choix 1 ",1,popup)
				CreateMenu("choix 2 ",2,popup)

SetGraphics CanvasGraphics(can)
Cls;Flip

While True
	WaitEvent
	Select CurrentEvent.ID
		Case EVENT_WINDOWCLOSE
			End
		Case EVENT_MOUSEUP
			Cls;DrawText "data:"+String(EventData()),200,200;Flip 1
			PopupWindowMenu(win,popup)
	End Select
Wend
End

Is there something missing ?
Is that SetGraphics halt every mouse events outside the graphics specified ?

Anyway to get a popupmenu drawn under mouse position ?