title: Cannot make DataGridView to bind to data source more than once
body: <p>I have a Winforms GUI app. I have a list of simple class called <code>FinishedTests_Loops_DGV</code>. This list is being added in a different thread (timer thread). After new class is added to the list (inside timer thread), I call <code>updateLoopsDGV()</code> which invokes the <code>DataGridView</code> and updates it:</p>
  
  <pre><code>public void updateLoopsDGV()
  {
      if (DGV_Loops.InvokeRequired)
      {
          DGV_Loops.BeginInvoke((MethodInvoker)delegate()
          {
              DGV_Loops.DataSource = FinishedTests_Loops_DGV;
          });
      }
  }
  </code></pre>
  
  <p>This works <strong>only one time</strong>, meaning that once first element is added to the list, I see the first line appears in <code>DataGridView</code>, but any further calls to <code>updateLoopsDGV()</code> do NOT add lines to <code>DataGridView</code>. I checked in the debugger that my list is, for example 4 elements long, and function is called, but I still only see 1 row in the <code>DataGridView</code>.</p>
  
  <p>Even when I try to update the <code>DataGridView</code> by pressing on some button (in GUI thread):</p>
  
  <pre><code>private void button3_Click(object sender, EventArgs e)
  {
      DGV_Loops.DataSource = FinishedTests_Loops_DGV;
  }
  </code></pre>
  
  <p>It still doesn't work. What am I doing wrong?</p>