Zellvergrößerung mit der Maus Probleme

procedure TFormMain.Button1Click(Sender: TObject);
var
  par, cell: TParagraph;
  Testzeile: TParagraph;
  Testzeile2: TParagraph;
  i:integer;
begin
  WPRichText1.Clear;
  Testzeile := WPRichText1.TableAdd(5, 2, []).ParentTable;
for i := 0 to 4 do
begin
  cell := Testzeile.rows[0].cols[i];
  cell.ASet(WPAT_COLWIDTH_PC,2000);
  cell := Testzeile.rows[1].cols[i];
  cell.ASet(WPAT_COLWIDTH_PC,2000);
end;
  cell := Testzeile.rows[0].cols[3];
  cell.SetText('Hallo');
  cell := Testzeile.rows[1].cols[3];
  cell.SetText('Du da');
  Testzeile.rows[1].cols[0].CellSelectionAdd;
  Testzeile.rows[1].cols[1].CellSelectionAdd;
  Testzeile.rows[1].cols[2].CellSelectionAdd;
  WPRichText1.CombineCells;
  WPRichText1.ReformatAll(true, true);
end;