Метод проверки IValidatableObject не работает

У меня есть этот класс, используемый в MVC3...

Атрибуты проверки для каждого свойства работают должным образом, но когда вызывается метод проверки и возвращаются какие-либо результаты, он не отправляется обратно в форму. Кто-нибудь может помочь??

public class Register : IValidatableObject
{
    [DataType(DataType.Text)]
    [Display(Name = "District Name")]
    [Required(AllowEmptyStrings = false, ErrorMessage = "You must enter a District Name")]
    [StringLength(40, MinimumLength = 1, ErrorMessage = "District Name must be between 1 and 40 characters")]
    public string DistrictName { get; set; }

    [DataType(DataType.Text)]
    [Display(Name = "Url Quick Find")]
    [Required(ErrorMessage = "You must provide a Quick Find Name")]
    [StringLength(15, MinimumLength = 3, ErrorMessage = "Url Quick Find must be between 3 and 15 characters")]
    public string QuickFind { get; set; }

    [DataType(DataType.Text)]
    [Display(Name = "User name")]
    [Required(AllowEmptyStrings = false, ErrorMessage = "User name is requred")]
    [StringLength(10, MinimumLength = 1, ErrorMessage = "Url Quick Find must be between 1 and 10 characters")]
    public string Username { get; set; }

    [DataType(DataType.Password)]
    [Display(Name = "Password")]
    [Required(AllowEmptyStrings = false, ErrorMessage = "Password is requred")]
    public string Password { get; set; }

    [DataType(DataType.Password)]
    [Display(Name = "Re-Enter Password")]
    [Required(AllowEmptyStrings = false, ErrorMessage = "You must re-enter your password to confirm you have entered it correctly")]
    public string PasswordConfirm { get; set; }

    [DataType(DataType.Text)]
    [Display(Name = "Display Name")]
    [Required(AllowEmptyStrings = false, ErrorMessage = "Display Name is requred")]
    [StringLength(20, MinimumLength = 1, ErrorMessage = "Display Name must be between 1 and 20 characters")]
    public string DisplayName { get; set; }

    [DataType(DataType.EmailAddress)]
    [Display(Name = "Email Address")]
    [Required(AllowEmptyStrings = false, ErrorMessage = "Email Address is requred")]
    [StringLength(50, MinimumLength = 4, ErrorMessage = "Email Address must be between 4 and 50 characters")]
    public string EmailAddress { get; set; }

    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        Regex lettersOnly = new Regex("^[a-zA-Z]*$");

        if (!lettersOnly.IsMatch(QuickFind))
            yield return new ValidationResult("Only letters A - Z are allowed in the Quick Find", new string[] { "QuickFind" });

        if (!lettersOnly.IsMatch(QuickFind))
            yield return new ValidationResult("Only letters A - Z are allowed for your User name", new string[] { "Username" });

        if (Password != PasswordConfirm)
            yield return new ValidationResult("Passwords do not match", new string[] { "Password", "PasswordConfirm" });

    }
}

Код контроллера:

[HttpPost]
    public ActionResult Index(Register registration)
    {
        try
        {
            User newUser = RegistrationManager.Register(registration);
            RedirectToAction("Index", "District", newUser.ID);
        }
        catch (Exception ex)
        {
            ModelState.AddModelError("There has been an Error during Registration", ex.Message);
            RedirectToAction("Details", "Error", ex);
        }

        return View();
    }

Просмотреть код:

@model PubGames.Data.Register
@{
    ViewBag.Title = "Register";
}
<h2>
    Register</h2>
<script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")"     type="text/javascript"></script>
@using (Html.BeginForm())
{
    @Html.ValidationSummary(true)

    <div class="editor-label">
        @Html.LabelFor(model => model.DistrictName)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.DistrictName)
        @Html.ValidationMessageFor(model => model.DistrictName)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.QuickFind)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.QuickFind)
        @Html.ValidationMessageFor(model => model.QuickFind)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.Username)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.Username)
        @Html.ValidationMessageFor(model => model.Username)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.Password)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.Password)
        @Html.ValidationMessageFor(model => model.Password)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.PasswordConfirm)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.PasswordConfirm)
        @Html.ValidationMessageFor(model => model.PasswordConfirm)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.DisplayName)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.DisplayName)
        @Html.ValidationMessageFor(model => model.DisplayName)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.EmailAddress)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.EmailAddress)
        @Html.ValidationMessageFor(model => model.EmailAddress)
    </div>

    <p>
        <input type="submit" value="Register" />
    </p>
}