procedure TForm6.BitBtn2Click(Sender: TObject);
var
  Cr : TIB_Cursor;
begin
  try
    Cr := TIB_Cursor.Create(nil); //quando estou numa unit utilizo o nil
    with Cr do
      begin
        IB_Connection := Conexao;
        SQL.Text      := 'select first 2 * from usuarios order by id';
        Open;
        while (not eof) do
          begin
            ShowMessage(FieldByName('Nome').AsString);
            Next;
          end;
      end;
  finally
    Cr.Close;
    Cr.UnPrepare;
    FreeAndNil(Cr);
  end;
  ShowMessage('Aqui');
end;