CheckListEdit problem

I would like to populate the items in a CheckListEdit component using the following code.  I added a button and an additional CheckListEdit to the CheckListEdit demo, and the following code for the button's OnClick event.  When I click on the button the items are loaded into the CheckListEdit.  If I view the items or check an item or two, and then click on the button again I get an error indicating that the "Control has no parent window".

procedure TForm1.Button1Click(Sender: TObject);
var stringlist : Tstringlist;
begin
  stringlist:=TStringList.Create;
  stringlist.Add('Item1');
  stringlist.Add('Item2');
  stringlist.Add('Item3');
  try
    CheckListEdit4.Items := stringlist;
  finally
    stringlist.Free;
  end;
end;

I tried adding the following prior to the "try finally" statement, but the error persists.
  CheckListEdit4.ClearSelection;
  CheckListEdit4.Items.Clear;
  CheckListEdit4.Clear;
  CheckListEdit4.Parent := self;
  CheckListEdit4.SetFocus;

I would appreciate any ideas for correcting this error.  In the actual application the stringlist can change and I want to update the CheckListEdit items when this happens. Thanks.

Paul