datagridview med combobox

Jeg har "lidt" problemer med en datagridview med en combobox i.

Jeg kan simpel hen ikke få data'en ud af den eller sætte et index/value i combobox'en.
Det er dog lykkes mig at lave selve combobox'en men den data i som der skal være.

En der kan forklare mig hvordan jeg f.eks. kan få data'en ud af
dataGridView1, row 0, collone 3 (som er en combobox).
Eller hvordan jeg kan sætte den?

Her er min kode so far!
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Indexer;
using SeriesIdentifier;
using SerieInfo;
using System.IO;
using System.Threading;
using System.Collections;
using System.Data.SqlClient;

namespace Seriesindexer
{
    public partial class SelectImdb : Form
    {
        public SelectImdb()
        {
            InitializeComponent();
        }

        private DatabaseDataSetTableAdapters.FilesTableAdapter TAFile = new Seriesindexer.DatabaseDataSetTableAdapters.FilesTableAdapter();
        private DatabaseDataSetTableAdapters.FoldersTableAdapter TAFolder = new Seriesindexer.DatabaseDataSetTableAdapters.FoldersTableAdapter();

        SerieSearch Search = new SerieSearch();
        DataTable _DataTable;
        DataRow dr;

        private void SelectImdb_Load(object sender, EventArgs e)
        {

            DataTable Shows = Populate("SELECT DISTINCT serie  FROM  Files");
            for (int i = 0; i < Shows.Rows.Count && i <= 2; i++)
            {
                ResetDataTable();
                if (Shows.Rows[i]["serie"].ToString() != "")
                {
                    ArrayList Serie = Search.GetImdbSelect(Shows.Rows[i]["serie"].ToString());
                    foreach (string[] s in Serie)
                    {
                        dr = this._DataTable.NewRow();
                        dr["text"] = s[0];
                        dr["value"] = s[1];
                        this._DataTable.Rows.Add(dr);
                    }

                    DataGridViewRow heterow = new DataGridViewRow();

                    DataGridViewComboBoxCell comboCell = new DataGridViewComboBoxCell();
                    comboCell.DataSource = _DataTable;
                    comboCell.ValueMember = "value";
                    comboCell.DisplayMember = "text";
                    DataGridViewCheckBoxCell checkbox = new DataGridViewCheckBoxCell();
                    checkbox.Value = true;
                    DataGridViewTextBoxCell FileName = new DataGridViewTextBoxCell();
                    FileName.Value = Shows.Rows[i]["serie"].ToString();
                    DataGridViewTextBoxCell imdb = new DataGridViewTextBoxCell();
                    imdb.Value = "";

                    heterow.Cells.Add(checkbox);
                    heterow.Cells.Add(FileName);
                    heterow.Cells.Add(comboCell);
                    heterow.Cells.Add(imdb);
                    dataGridView.Rows.Add(heterow);
                }
            }
        }

        private void ResetDataTable()
        {
            _DataTable = new DataTable();
            DataColumn dc;
            dc = new DataColumn("text", System.Type.GetType("System.String"));
            this._DataTable.Columns.Add(dc);
            dc = new DataColumn("value", System.Type.GetType("System.String"));
            this._DataTable.Columns.Add(dc);
            dr = this._DataTable.NewRow();
            dr["text"] = "Custom";
            dr["value"] = "";
            this._DataTable.Rows.Add(dr);
        }

        private void buttonFinished_Click(object sender, EventArgs e)
        {
        }

        private void ComboBox_SelectedIndexChanged(object sender, EventArgs e)
        {
            try
            {
                string txt = ((ComboBox)sender).SelectedValue.ToString();
                int rowIndex = this.dataGridView.CurrentRow.Index;
                DataGridViewRow row = this.dataGridView.Rows[rowIndex];
                this.dataGridView[3, rowIndex].Value = string.Format("{0}", txt);
            }
            catch
            { }
        }


        private void dataGridView_EditingControlShowing(object sender,
            DataGridViewEditingControlShowingEventArgs e)
        {
            if (dataGridView.CurrentCell.ColumnIndex == 3)
            {
                // If we are editing the imdb link
                // ARGH set combobox til custom, for crying out loud!!

            }

            ComboBox combo = e.Control as ComboBox;
            if (combo != null)
            {
                // Remove an existing event-handler, if present, to avoid
                // adding multiple handlers when the editing control is reused.
                combo.SelectedIndexChanged -=
                    new EventHandler(ComboBox_SelectedIndexChanged);

                // Add the event handler.
                combo.SelectedIndexChanged +=
                    new EventHandler(ComboBox_SelectedIndexChanged);
            }
        }
        private DataTable Populate(string sqlCommand)
        {
            SqlConnection northwindConnection = new SqlConnection(global::Seriesindexer.Properties.Settings.Default.DatabaseConnectionString);
            northwindConnection.Open();

            SqlCommand command = new SqlCommand(sqlCommand, northwindConnection);
            SqlDataAdapter adapter = new SqlDataAdapter();
            adapter.SelectCommand = command;

            DataTable table = new DataTable();
            table.Locale = System.Globalization.CultureInfo.InvariantCulture;
            adapter.Fill(table);

            return table;
        }
    }
}