anchor.diff:    if not HasHandle then
       Exit; //==>
     FRecalc := True;
  -  Invalidate;//  DrawSlider(True);
  +  Invalidate;
   end;
   
   procedure TfpgScrollBar.LineUp;
  
positive.code:     DrawButton(0, 0, Height, Height, 'sys.sb.left', (FScrollbarDownPart = sbpUpBack) and (FPosition <> FMin), (FPosition <> FMin) and (Parent.Enabled));
      DrawButton(Width-Height, 0, Height, Height, 'sys.sb.right', (FScrollbarDownPart = sbpDownForward) and (FPosition <> FMax), (FPosition <> FMax) and (Parent.Enabled));
    end;
  
    DrawSlider(FRecalc);
    Canvas.EndDraw;   // Do not remove - Scrollbars do painting outside HandlePaint as well!
    FRecalc := False;
  end;
  
  
negative.code:     FSliderPos := area;
  
    if ppos <> FSliderPos then
      Invalidate;
  
    if area <> 0 then
      newp := FMin + Trunc((FMax - FMin)  * (FSliderPos / area))
  