title: await ExecuteNonQueryAsync() still blocks my UI
body: <p>I find that my C# app UI hangs when calling an async method, I cannot figure out why.</p>
  
  <pre><code>private async void selectCSVFileButton_Click(object sender, EventArgs e)
  {
      ... 
      var results = await ntz.getProductNames();
      ...
  }
  ...
  public async Task&lt;List&lt;string[]&gt;&gt; getProductNames()
  {
      string fmt = "DRIVER={{NetezzaSQL}};SERVER={0};PORT={1};DATABASE={2};UID={3};PWD={4};";
      ntz = new OdbcConnection(string.Format(fmt, server, port, db, user, password));
      await ntz.OpenAsync();
      qry = "SELECT * FROM ak_db_1 WHERE prod_name_desc='Unknown'";
      OdbcCommand cmd = ntz.CreateCommand();
      cmd.CommandTimeout = 600;
      cmd.CommandText = qry;
      await cmd.ExecuteNonQueryAsync();
      ...
  }
  </code></pre>
  
  <p>My application hangs completely (UI unresponsive) until the cmd.ExecuteNonQueryAsync completes.  Any ideas?</p>