UPDATE:

My model going into the save method is PartialViewModel, which in the save method, is pushed into the index's ContactViewModel and sent back. This wasn't clear.

I am playing around with MVC3, and have a contact controller with a SaveDetails action. The index cshtml has a partial with a form whose action is pointing to this controller.

When I submit the form not having completed it fully, thereby firing the validation, the url now contains the SaveDetails action name (http://localhost:7401/Contact/SaveDetails).

The form code is:

@using (Html.BeginForm("SaveDetails", "Contact")) {
    ...
}

The controller action looks like this:

public ActionResult SaveDetails(Models.PartialsViewModel pvm)
{
    return View("Index", new ContactViewModel{ PartialsViewModel = pvm } );
}

What am I doing wrong?