title: MVC Html.CheckBox and form submit issue
body: <p>Crazy issue with submitting of values in Html.Checkbox in ASP.NET MVC RC</p>
  
  <p>Some of the values are just not come to Request.Params</p>
  
  <p>At my form I have this line inside the cycle: <br><br>
  <code>&lt;%=Html.CheckBox("cb" + p.Option.Id, p.Option.IsAllowed, new { value = 6 })%&gt;</code></p>
  
  <p>and it renders to next:</p>
  
  <pre><code>    &lt;input checked="checked" id="cb17" name="cb17" type="checkbox" value="6" /&gt;
  &lt;input name="cb17" type="hidden" value="false" /&gt; 
  
      &lt;input checked="checked" id="cb18" name="cb18" type="checkbox" value="6" /&gt;
  &lt;input name="cb18" type="hidden" value="false" /&gt; 
  
      &lt;input id="cb19" name="cb19" type="checkbox" value="6" /&gt;
  &lt;input name="cb19" type="hidden" value="false" /&gt;
  
      &lt;input id="cb20" name="cb20" type="checkbox" value="6" /&gt;
  &lt;input name="cb20" type="hidden" value="false" /&gt;
  
      &lt;input checked="checked" id="cb21" name="cb21" type="checkbox" value="6" /&gt;
  &lt;input name="cb21" type="hidden" value="false" /&gt; 
  </code></pre>
  
  <p>After submitting the Form I'm get something like:</p>
  
  <pre><code>Form.Params["cb17"] = {6, "false"}
  Form.Params["cb18"] = {6, "false"}
  Form.Params["cb19"] = {"false"}
  Form.Params["cb20"] = {"6,false"}
  Form.Params["cb21"] = {"false"}
  </code></pre>
  
  <p>In the request string Some of the params are displayed twice (normal situation) and some only ONE TIME (only value of hidden field). 
  It seems that it doesn't rely on whether checkbox was checked or not, whether value has changed or so...</p>
  
  <p>Does anybody faced with such a situation? How can I work around?</p>