OutputCache does not let to change site's language in mcv3

 I want to use OutputCache to open pages more quickly. There is 2 languages in site ( LanguageResource.resx and LanguageResource.az.resx). In controller: 

public class HomeController : Controller { [OutputCache(Duration=3600,VaryByParam="none", VaryByCustom="lang")] public ActionResult Index() { //........ } public ActionResult ChangeCulture( string lang, string returnUrl ) { Session["Culture"] = new CultureInfo( lang ); return Redirect( returnUrl ); } }
In Layout.cshtml:


<a href="@Url.Action( "ChangeCulture", "Home", new { lang = "en", returnUrl = this.Request.RawUrl } )">Eng</a> <a href="@Url.Action( "ChangeCulture", "Home", new { lang = "az", returnUrl = this.Request.RawUrl } )">Az</a>

In Global.asax I wrote:
 
pro ...