anchor.diff:    fScrollBar.MaxValue := Math.max(fItems.Count - (fHeight div fItemHeight), 0);
     fScrollBar.Position := fTopIndex;
     fScrollBar.Enabled := fScrollBar.MaxValue > fScrollBar.MinValue;
  +  fScrollBar.Visible := fScrollBar.Visible and (not fAutoHideScrollBar or fScrollBar.Enabled);
   end;
   
   
  
positive.code: 
  
  //Hide the scrollbar if it is not required (disabled) This is used for drop boxes.
  procedure TKMListBox.AutoHideScrollBar;
  begin
     fScrollBar.Visible := Visible and fScrollBar.Enabled;
  end;
  
  
  
negative.code: procedure TKMListBox.SetVisible(aValue:boolean);
  begin
    Inherited;
    fScrollBar.Visible := fVisible and (not fAutoHideScrollBar or fScrollBar.Enabled); //Hide scrollbar and its buttons
  end;
  
  
  