To reproduce:

public Form1()
{
    InitializeComponent();

    this.radGridView1.Columns.Add("Col1");
    this.radGridView1.Rows.Add("word \u00AD word");
    this.radGridView1.Rows.Add("word - word");
}

Workaround: replace "\u00AD" with "-"

private void radGridView1_CellFormatting(object sender, Telerik.WinControls.UI.CellFormattingEventArgs e)
{
    e.CellElement.Text = e.CellElement.Text.Replace("\u00AD", "-");
}