🚀 go-pugleaf

Sorry if I have already asked this question, but I can't remember if I posted
it yet or not - too many late nights, I guess.

I have implemented a floating window that hangs around and shows the (x,y)
of the cursor as it moves around the screen. I create it as a child window 
with a height equal to the height of the caption area, so all you get is the
system menu handle and a caption area.  Each time I get WM_MOUSEMOVE, I
SetWindowText(hwndxy,"...").  It works great and is really tiny (1 line).

However, I am not getting the expected results using window class style 
CS_SAVEBITS.  I don't want movement of the floating (x,y) window to 
generate WM_PAINT for the client area underneath if I don't have to.  The
help says that if style is CS_SAVEBITS, then it will try to save the bitmap 
behind the window so it can restore it.  Presumably then it won't have to
send WM_PAINT to the client beneath it.  No such luck.  There is tons of
memory available and it sure enough saves bitmaps for popup dialog boxes
to restore quickly.  Why won't it do it for my tiny little window?

I register the class with:
	wc.style=CS_SAVEBITS;         

and then I create the window with:        
	hwndxy=CreateWindow("xy",NULL,
	     WS_CHILD | WS_VISIBLE | WS_CAPTION | WS_BORDER | WS_SYSMENU,
	     0,0,                    
	     200,GetSystemMetrics(SM_CYCAPTION),
	     hwnd,                   
	     (HMENU)1,  //child id=1
	     hinstance,
	     NULL);