Remote validator return null value.

[Juan Pablo Perez]

I have a form with some controls, meanwhile remote validator for normal text control works perfectly in the same form the remote validator for a DatePickedFor Telerik control return allways null. Does anybody know how to resolve this problem?
Thanks in advance.

@(Html.Telerik().DatePickerFor(x => x.Model.Birthdate)
           .InputHtmlAttributes(new { @class = "FormDate" })
           .ShowButton(true)
           .Min(DateTime.Now.AddYears(-150))
           .Max(DateTime.Now.AddYears(-18))
           .Value(Model.Model.Birthdate)
   )