anchor.diff:  
     TJvDockCustomPanel = class(TJvDockCustomControl)
     protected
  +    procedure WMEraseBkgnd(var Message: TWmEraseBkgnd); message WM_ERASEBKGND;
       function CreateDockManager: IDockManager; override;
     public
       constructor Create(AOwner: TComponent); override;
  
positive.code: constructor TJvDockPageControl.Create(AOwner: TComponent);
  begin
    inherited Create(AOwner);
    ControlStyle := [csDoubleClicks, csParentBackground, csOpaque];
    FPages := TList.Create;
    FTabSheetClass := TJvDockTabSheet;
  end;
  
negative.code: constructor TJvDockCustomPanel.Create(AOwner: TComponent);
  begin
    inherited Create(AOwner);
    // csParentBackground will be removed after the initial drawaing of the control
    ControlStyle := [csAcceptsControls, csCaptureMouse, csClickEvents,
      csSetCaption, csParentBackground, csOpaque, csDoubleClicks, csReplicatable];
    Color := clBtnFace;
  