Что не так с потоком?

constructor TChangeMonitor.Create(ASuspended: boolean; ADirectory: string;
  AScanSubDirs: boolean);
begin
  inherited Create(ASuspended);
  FDirectory := ADirectory;
  FScanSubDirs := AScanSubDirs;
  FreeOnTerminate := true;
end;
 
procedure TChangeMonitor.DoChange;
begin
  if Assigned(FOnChange) then
    OnChange(Self)
end;
 
procedure TChangeMonitor.Execute;
var
  ChangeHandle: THandle;
begin
  ChangeHandle := FindFirstChangeNotification(PChar(FDirectory), FScanSubDirs,
    FILE_NOTIFY_CHANGE_FILE_NAME);
  Win32Check(ChangeHandle <> INVALID_HANDLE_VALUE);
  try
    while not Terminated do
    begin
      case WaitForSingleObject(ChangeHandle, INFINITE) of
        WAIT_FAILED:
          Terminate;
        WAIT_OBJECT_0:
          Synchronize(DoChange);
      end;
      FindNextChangeNotification(ChangeHandle);
    end;
  finally
    FindCloseChangeNotification(ChangeHandle);
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  Memo1.Lines.Clear;
  FChangeMonitor := TChangeMonitor.Create(True, Edit1.Text, CheckBox1.Checked);
  FChangeMonitor.OnChange := OnChange;
  FChangeMonitor.Start;
end;
 
procedure TForm1.Button2Click(Sender: TObject);
begin
  FChangeMonitor.Terminate;
end;
 
procedure TForm1.OnChange(Sender: TObject);
const
  cLogStr = '%s - Attention';
begin
  Memo1.Lines.Add(Format(cLogStr, [DateTimeToStr(Now)]));
end;