Erro na execução do ajax

        [HttpPost]
        [ValidateAntiForgeryToken()] 
        public ActionResult AutenticaUsuario(string username, string password, bool rememberme, string acesso)
        {
            LoginModel loginModel = new LoginModel();
            loginModel.Usuario = username;
            loginModel.Senha = password;
            loginModel.Acesso = acesso;
            string msgErro = string.Empty;
            CustomAutenticacaoProvider autenticacaoProvider = new CustomAutenticacaoProvider();
            if (autenticacaoProvider.Autenticar(loginModel, out msgErro))
            {
                return Json(true, JsonRequestBehavior.AllowGet);
            }
            else
            {
                return Json(false, JsonRequestBehavior.AllowGet);
            }
        }

JS

GeoMailing.Identity = {
    LoginIntoStd: function (username, password, rememberme, acesso, antiForgeryToken, successCallback, failureCallback) {
        var data = { "__RequestVerificationToken": antiForgeryToken, "username": username, "password": password, "rememberme": rememberme, "acesso": acesso };

        $.ajax({
            url: "/Home/AutenticaUsuario",
            type: "POST",
            data: data
        })
        .done(function (loginSuccessful) {
            if (loginSuccessful) {
                successCallback();
            }
            else {
                failureCallback("Tentativa de login inválida.");
            }
        })
        .fail(function (jqxhr, textStatus, errorThrown) {
            failureCallback(errorThrown);
        });
    }
}