That is because the View never moves... The view window is actually a child window of your CChildFrame (from CMDIChildWnd), and (almost) always sits at (0,0). When you drag the "View" about, you are actually dragging the frame about. The view sits still relative to its parent window. When you resize the "View", you actually resize the frame. The frame resizes the View, which is why you get WM_SIZE messages! If you really need to know that you've moved, move your functionality into CChildFrame. The child frame can be useful, as you can (e.g) toolbars to each frame, instead of just having the main ones. Hopefully that made sense! Iain.