title: knockout radio group inside foreach binding works one way only
body: <p>Im using Knockout JavaScript library v2.2.0rc.</p>
  
  <p>I wonder, whether it is possible to do the following.</p>
  
  <p>my template looks like this</p>
  
  <pre><code>&lt;script type="text/html" id="@Html.UniqueId("WorkflowRulesDisplay_template")"&gt;
  &lt;div data-bind ="foreach: items"&gt;
      &lt;fieldset&gt;
          &lt;legend&gt;
              &lt;span data-bind="text: StName"/&gt;
          &lt;/legend&gt;
          &lt;dl class="row"&gt;
              &lt;dt class="label"&gt;
                  &lt;label&gt;Member Type:&lt;/label&gt;
              &lt;/dt&gt;
              &lt;dd class="field"&gt;
                  &lt;div&gt;&lt;input type="radio" value = "User" data-bind="attr :{name:'@Html.UniqueId("wf_usr_radio_grp_")' + StId, checked: CheckedUsr}"/&gt;User&lt;/div&gt;
                  &lt;div&gt;&lt;input type="radio" value = "Group" data-bind="attr :{name:'@Html.UniqueId("wf_usr_radio_grp_")' + StId, checked: CheckedGrp}" /&gt;Group&lt;/div&gt;
              &lt;/dd&gt;
          &lt;/dl&gt;
          &lt;dl class="row"&gt;
              &lt;dt class="label"&gt;
                  &lt;label&gt;Description:&lt;/label&gt;
              &lt;/dt&gt;
              &lt;dd class="field"&gt;
                  &lt;textarea rows ="5" cols="20" class ="textbox simple-text" data-bind="value: Description"&gt;&lt;/textarea&gt;
              &lt;/dd&gt;
          &lt;/dl&gt;
      &lt;/fieldset&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p></p>
  
  <p>My viewmodel and init code looks like this:</p>
  
  <pre><code>this._items = ko.observableArray(workflow.data('workflow_list_data'));
  var viewModel = { items: this._items};
  ko.applyBindingsToNode(this._containerElem.get(0), { template: { name:workflow.attr('id').replace('_workflow_control', '_template') } }, viewModel);
  </code></pre>
  
  <p>where workflow.data('workflow_list_data') is</p>
  
  <pre><code>data.Select(x =&gt; new { StName = x.StatusType != null ? x.StatusType.Name : string.Empty, StId = x.SuccessorStatusId, CheckedGrp = !x.GroupId.HasValue, CheckedUsr = !x.UserId.HasValue, x.UserId, x.GroupId, x.Description });
  </code></pre>
  
  <p>, so client-side, I have this: [Object{StName="lala", StId=123, CheckedGrp=false, CheckedUsr=true, Description="lala"}....{...}] </p>
  
  <p>It all goes fine, but the radio group. Changing the selected button never changes the viewmodel. Ive tried checked and attr-value binding - all the same.</p>