title: CheckboxList ignores DataValueField and DataTextField
body: <p>I found the bug. It was so plain in sight: I'm not databinding to the correct checkboxlist! I should have been databinding to filterONTYPElist, but i'm databinding to the filterONDATASETlist... Copy paste error, sorry...</p>
  
  <p>I have a checkboxlist that renders as follows:</p>
  
  <p><img src="https://i.stack.imgur.com/LKk1r.png" alt="enter image description here"></p>
  
  <p>Here is the code that handles the databinding:</p>
  
  <pre><code>FilterOnTypeCheckboxList.DataSource = listCheckboxItems;
  FilterOnDatasetCheckboxList.DataValueField = "Value";
  FilterOnDatasetCheckboxList.DataTextField = "Text";
  FilterOnTypeCheckboxList.DataBind();
  </code></pre>
  
  <p>My datasource is a <code>list&lt;CheckBoxItem&gt;</code>. That class looks as follow, and you can clearly see there is a public property Value and a public property Text:</p>
  
  <pre><code>[Serializable]
  public class CheckboxItem
  {
      public string Text { get; set; }
      public string Value { get; set; }
  
      public CheckboxItem(string value, string text)
      {
          Value = value;
          Text = text;
      }
  
      public override string ToString()
      {
          return "brompot";
      }
  }
  </code></pre>
  
  <p>But for some reason, the text AND value for each checkbox uses the ToString() method of the CheckBoxItem class, rather then the appropiate property "Value" and "Text".</p>
  
  <p>PS: I checked that the value and the text of the checkboxitems objects is not the string "brompot"... </p>
  
  <p>It is not an option to let the toString() method return the text OR the value, because I want the checkbox value to be the value property and the checkbox (label) text </p>