MVC3 does not accept cookies

I just started my first MVC3 app and everything works fine except for cookie authorization. When a user visits my site and registers, I set a cookie.ASPAUTH with information about that user. It works well until some time passes. Then I need to log in again even though the cookie is in the browser and I see that it expires after a year. It works fine on my localhost. It seems to me that instead of setting my information to a cookie, it is somehow in session, but even if I restart my computer for an hour, I still log in. But if I don't go online after 1 hour, I am logged out.

Thanks for any help.

FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(
                1,
                requestedUser.Name,
                DateTime.Now,
                DateTime.Now.AddYears(1),
                true,
                string.Format("{0};{1};{2}", requestedUser.IDUser.ToString(), requestedUser.IsAdmin.ToString(), profilePicture));

            string encryptedTicket = FormsAuthentication.Encrypt(ticket);
            HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName, encryptedTicket);
            cookie.Expires = keepLogged == "keepLogged" ? DateTime.Now.AddYears(1) : DateTime.Now.AddHours(1);

            this.Response.Cookies.Add(cookie);
            return RedirectToAction("Index", "Posts");