To reproduce:
protected override void OnLoad(EventArgs e)
{
    this.radGridView1.AllowAddNewRow = false;
    this.radGridView1.TableElement.RowHeight = 40;

    this.radGridView1.MasterTemplate.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;        
    GridViewTextBoxColumn id = new GridViewTextBoxColumn("ID");
    id.IsVisible = false;
    GridViewTextBoxColumn parentID = new GridViewTextBoxColumn("ParentID");
    parentID.IsVisible = false;
    GridViewTextBoxColumn name = new GridViewTextBoxColumn("Name");
    GridViewDateTimeColumn date = new GridViewDateTimeColumn("Date");
    GridViewTextBoxColumn type = new GridViewTextBoxColumn("Type");
    GridViewTextBoxColumn size = new GridViewTextBoxColumn("Size");
    size.FormatString = "{0} MB";
    radGridView1.Columns.AddRange(new GridViewDataColumn[]
    {
        id,
        parentID,
        name,
        date,
        type,
        size
    });

    this.radGridView1.Relations.AddSelfReference(this.radGridView1.MasterTemplate, "ID", "ParentID");

    radGridView1.CellValueChanged += radGridView1_CellValueChanged;
    fillData();
}



void radGridView1_CellValueChanged(object sender, GridViewCellEventArgs e)
{
    fillData();
}

private void fillData()
{     
    radGridView1.Rows.Clear();
   
    radGridView1.Rows.Add(1, null, "Program Files", DateTime.Now.AddDays(-100), "Folder", 5120);
    radGridView1.Rows.Add(2, 1, "Visual Studio 2010", DateTime.Now.AddDays(-100), "Folder", 3220);
    radGridView1.Rows.Add(3, 2, "bin", DateTime.Now.AddDays(-100), "Folder", 3220);
    radGridView1.Rows.Add(4, 2, "READEME.txt", DateTime.Now.AddDays(-100), "Text Document", 3);
    radGridView1.Rows.Add(100, null, "Test.txt", DateTime.Now.AddDays(-10), "Text File", 0);

    radGridView1.Rows.Add(5, 1, "Telerik RadControls", DateTime.Now.AddDays(-10), "Folder", 3120);
    radGridView1.Rows.Add(6, 5, "Telerik UI for Winforms", DateTime.Now.AddDays(-10), "Folder", 101);
    radGridView1.Rows.Add(7, 5, "Telerik UI for Silverlight", DateTime.Now.AddDays(-10), "Folder", 123);
    radGridView1.Rows.Add(8, 5, "Telerik UI for WPF", DateTime.Now.AddDays(-10), "Folder", 221);
    radGridView1.Rows.Add(9, 5, "Telerik UI for ASP.NET AJAX", DateTime.Now.AddDays(-10), "Folder", 121);

    radGridView1.Rows.Add(10, 1, "Microsoft Office 2010", DateTime.Now.AddDays(-120), "Folder", 1230);
    radGridView1.Rows.Add(11, 10, "Microsoft Word 2010", DateTime.Now.AddDays(-120), "Folder", 1230);
    radGridView1.Rows.Add(12, 10, "Microsoft Excel 2010", DateTime.Now.AddDays(-120), "Folder", 1230);
    radGridView1.Rows.Add(13, 10, "Microsoft Powerpoint 2010", DateTime.Now.AddDays(-120), "Folder", 1230);

    radGridView1.Rows.Add(14, 1, "Debug Diagnostic Tools v1.0", DateTime.Now.AddDays(-400), "Folder", 2120);
    radGridView1.Rows.Add(15, 1, "Designer's 3D Tools", DateTime.Now.AddDays(-500), "Folder", 1120);
    radGridView1.Rows.Add(16, 1, "Communication", DateTime.Now.AddDays(-700), "Folder", 120);
}

Then start the application edit a value and click another cell.

Workaround:
- Enclose the rows addition within Begin/End update block.