title: DropDownListFor Not Selecting Value even when Selected property evaluates to true
body: <p>I'm new to ASP MVC. My dropdown is not selecting any item although my debugger stops here on conditional breakpoint, when Selected condition expression is evaluated as true. 
  Model here is my custom ViewModel for this view and Model.Department is same type as department in ViewBag.PossibleDepartments.
  Am I missing something here?</p>
  
  <pre><code>@Html.DropDownListFor(model =&gt; model.Department, 
  ((IEnumerable&lt;Invoices.Web.Domain.Department&gt;)ViewBag.PossibleDepartments)
   .Select(option =&gt; new  
            SelectListItem 
            {
             Text = (option == null ? "none" : option.Name),
             Value = (option == null ? string.Empty : option.Id.ToString()),
             Selected = (Model != null &amp;&amp; option != null &amp;&amp;
                       Model.Department!= null &amp;&amp; option == Model.Department)
            }
          ), "Choose...") 
  </code></pre>
  
  <p><strong>Update</strong>:
  I have put that code to the service that provides the model and added DepartmentSelectList property but the Selected property comes always as false. Also I only get System.Web.Mvc.SelectListItem options rendered in dropdown when initializing list with IEnumerable from model. What is wrong with this SelectList class?</p>
  
  <p>Model.<strong>Department</strong> is my EF Code First model but user (UserModel) who belongs to this department is not from EF entities. I needed to provide also IsAdmin property which has to be managed via WebSecurity API, so I had to add fields for <strong>Employee</strong> entity to the UserModel and add IsAdmin, so that I can edit role from single view. I'm still quite lost in MVC and can't see correct pattern for this scenario. I would be thankful for some directions/links to this kind of practices in MVC.</p>