Is it possible, that Resx Localization only work in PCL Projects?

I´ve tried to set up my Cross Platform App(SAP) to multiple languages. I´ve did it exactly as described in the Localizing Xamarin docs.
First of all I could´t find a way to add a resource file. It was not available und Add > New File.

After a lot of hours in the Xamarin Forum reading post after post, I´ve created a PCL Project with the same Namespace and added a Resource File. The PCL works fine.
So I copied the Resource Files to may SAP Project.

Now, every time I try to run it, I get a "System.Resources.MissingManifestResourceException"

System.Runtime.CompilerServices.AsyncVoidMethodBuilder.AnonymousMethod__0 (l={System.Resources.MissingManifestResourceException: Could not find any resources appropriate for the specified culture or the neutral culture.  Make sure "SubitoEvents.Resx.AppResources.resources" was correctly embedded or linked into assembly "SubitoEventsiOS" at compile time, or that all the satellite assemblies required are loadable and fully signed.
  at System.Resources.ResourceManager.AssemblyResourceMissing (System.String fileName) [0x0004d] in /Developer/MonoTouch/Source/mono/mcs/class/corlib/System.Resources/ResourceManager.cs:506 
  at System.Resources.ResourceManager.InternalGetResourceSet (System.Globalization.CultureInfo culture, Boolean createIfNotExists, Boolean tryParents) [0x0013e] in /Developer/MonoTouch/Source/mono/mcs/class/corlib/System.Resources/ResourceManager.cs:399 
  at System.Resources.ResourceManager.InternalGetResourceSet (System.Globalization.CultureInfo culture, Boolean createIfNotExists, Boolean tryParents) [0x0020a] in /Developer/MonoTouch/Source/mono/mcs/class/corlib/System.Resources/ResourceManager.cs:428 
  at System.Resources.ResourceManager.GetString (System.String name, System.Globalization.CultureInfo culture) [0x0002e] in /Developer/MonoTouch/Source/mono/mcs/class/corlib/System.Resources/ResourceManager.cs:252 
  at SubitoEvents.Resx.AppResources.get_ButtonForward () [0x00010] in /Users/cetei5/Projects/EventsCenter/SubitoEvents/Resx/AppResources.Designer.cs:70 
  at SubitoEvents.Views.LogInPage..ctor () [0x003ab] in /Users/cetei5/Projects/EventsCenter/SubitoEvents/Views/LogInPage.cs:202 
  at SubitoEvents.Views.MsgListPage+<ToLogInPage>c__async1.MoveNext () [0x00022] in /Users/cetei5/Projects/EventsCenter/SubitoEvents/Views/MsgListPage.cs:439 }) in /Developer/MonoTouch/Source/mono/mcs/class/corlib/System.Runtime.CompilerServices/AsyncVoidMethodBuilder.cs:79

So I went back to Xamarin Forum to find out why, again for hours without any success.
Meanwhile it seems that I´d been wasting my time.

Is there anybody who could provide me a working sample or could tell me that it´s not possible to use ResX Localisation with SAP Projects?

Thx a lot for every useful comment