c # Microsoft Access converting date

I'm having problems with INSERT and UPDATE because on my machine dates are being converted automatically, but not on users' machines.

Ex:

OleDbCommand cmd = new OleDbCommand("UPDATE tblPendencia " +
                                      " SET CarenciaInicio = " + (String.IsNullOrEmpty(pendencia.CarenciaInicioData.Trim()) ? "null" : "#" + pendencia.CarenciaInicioData + "#") + "," +
                                          " CarenciaFim = " + (String.IsNullOrEmpty(pendencia.CarenciaFimData.Trim()) ? "null" : "#" + pendencia.CarenciaFimData + "#") + "," +
                                          " AberturaData = " + (pendencia.AberturaData == null ? "null" : "#" + pendencia.AberturaData + "#") + "," +
                                          " VencimentoData = " + (pendencia.VencimentoData == null ? "null" : "#" + pendencia.VencimentoData + "#") + "," +
                                          " LiquidacaoData = " + (pendencia.LiquidacaoData == null ? "null" : "#" + pendencia.LiquidacaoData + "#") + "," +
                                          " CentroCusto = '" + pendencia.CentroCusto + "'," +
                                          " DiasDecorridos = " + pendencia.DiasDecorridos + "," +
                                          " Lastro = '" + pendencia.Lastro + "'," +
                                          " Corretora = '" + pendencia.Corretora + "'," +
                                          " AdAm = '" + pendencia.AdAm + "'," +
                                          " Observacao = '" + pendencia.Observacao + "'," +
                                          " Officer = '" + pendencia.Officer + "'," +
                                          " Segmento = '" + pendencia.Segmento + "'," +
                                          " Rating = '" + pendencia.Rating + "'," +
                                          " AlcadaTipo = '" + pendencia.AlcadaTipo + "'," +
                                          " Tipo = '" + pendencia.Tipo + "'" +
                                    " WHERE pendenciaNassauId = " + pendencia.PendenciaId, conn);

cmd.ExecuteNonQuery();

Running these queries on my machine will save on access to the date 11/07/2011, but if a user runs on his machine it will save correct: 07/11/2011.

In desperation I changed the language of office windows and even VS2013 on my machine, but it did not work.

Parameters: (error datatype mismatch)

using (OleDbConnection conn = new OleDbConnection(Conexao.getConexao()))
{
    conn.Open();

    using(OleDbCommand cmd = conn.CreateCommand())
    {
        cmd.CommandText = "INSERT INTO tblLog "+
                          "([operadorId], [logTipoId], [logData], [pendenciaId], [valorFatorAnterior], [valorFatorNovo], [statusIdAnterior], [statusIdNovo], [porContratoIdAnterior], [porContratoIdNovo], [isAtivo]) " +
                          "VALUES ( @operadorId, @logTipoId, @logData, @optionalPendenciaId, @optionalValorFatorAnterior, @optionalValorFatorNovo, @optionalStatusIdAnterior, @optionalStatusIdNovo, @optionalPorContratoIdAnterior, @optionalPorContratoIdNovo, @optionalIsAtivo);";

        cmd.Parameters.AddRange(new OleDbParameter[]
        {
            new OleDbParameter("@operadorId", operadorId),
            new OleDbParameter("@logTipoId", logTipoId),
            new OleDbParameter("@logData", logData ),
            new OleDbParameter("@optionalPendenciaId", optionalPendenciaId),
            new OleDbParameter("@optionalValorFatorAnterior", "'" + optionalValorFatorAnterior + "'"),
            new OleDbParameter("@optionalValorFatorNovo", "'" + optionalValorFatorNovo + "'"),
            new OleDbParameter("@optionalStatusIdAnterior", optionalStatusIdAnterior),
            new OleDbParameter("@optionalStatusIdNovo", optionalStatusIdNovo),
            new OleDbParameter("@optionalPorContratoIdAnterior", optionalPorContratoIdAnterior),
            new OleDbParameter("@optionalPorContratoIdNovo", optionalPorContratoIdNovo),
            new OleDbParameter("@optionalIsAtivo", optionalIsAtivo.ToString())                        
        });

        cmd.ExecuteNonQuery();
    }
}

I tested the form below but is giving datatype mismatch.

cmd1 = new OleDbCommand();
cmd1.CommandType = CommandType.Text;

cmd1.CommandText = "INSERT INTO tblLog " +
                           "([operadorId], [logTipoId], [logData], [pendenciaId], [valorFatorAnterior], [valorFatorNovo], [statusIdAnterior], [statusIdNovo], [porContratoIdAnterior], [porContratoIdNovo], [isAtivo]) " +
                   "VALUES ( ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);";

cmd1.Parameters.AddWithValue("@operadorId", operadorId);
cmd1.Parameters.AddWithValue("@logTipoId", logTipoId);
cmd1.Parameters.AddWithValue("@logData", logData );
cmd1.Parameters.AddWithValue("@optionalPendenciaId", optionalPendenciaId);
cmd1.Parameters.AddWithValue("@optionalValorFatorAnterior", optionalValorFatorAnterior);
cmd1.Parameters.AddWithValue("@optionalValorFatorNovo", optionalValorFatorNovo);
cmd1.Parameters.AddWithValue("@optionalStatusIdAnterior", optionalStatusIdAnterior);
cmd1.Parameters.AddWithValue("@optionalStatusIdNovo", optionalStatusIdNovo);
cmd1.Parameters.AddWithValue("@optionalPorContratoIdAnterior", optionalPorContratoIdAnterior);
cmd1.Parameters.AddWithValue("@optionalPorContratoIdNovo", optionalPorContratoIdNovo);
cmd1.Parameters.AddWithValue("@optionalIsAtivo", optionalIsAtivo);

cmd1.Connection = conn1;
cmd1.ExecuteNonQuery();

conn1.Close();