Eu sou novo com o Facebook SDK no iOS. Por que eu recebo esse erro enquanto construo o projeto ...

Acabei de criar um novo projeto com o passo básico do tutorial do ios para o Facebook SDK.

Faça o download do Facebook SDK (eu uso 3.1.1)Xcode (eu uso 4.5.2)adicionando "-lsqlite3.0" emOther Linker Flags emBuild Settingadicionando FacebookSDK.frameworkadicionando FacebookSDKResources.bundleadicionando FBUserSettingsViewResources.bundle

e eu tento construir, tudo bem .. então eu continuo escrevendo a implementação básica no AppDelegate

- (BOOL)application:(UIApplication *)application
            openURL:(NSURL *)url
  sourceApplication:(NSString *)sourceApplication
         annotation:(id)annotation {
    return [FBSession.activeSession handleOpenURL:url];
}

e

#import <FacebookSDK/FacebookSDK.h>

Quando eu tento construir, o erro está saindo ... Este é o log

Undefined symbols for architecture armv7:
  "_OBJC_CLASS_$_ACAccountStore", referenced from:
      objc-class-ref in FacebookSDK(FBSession.o)
  "_ACFacebookAudienceFriends", referenced from:
      -[FBSession authorizeUsingSystemAccountStore:accountType:permissions:defaultAudience:isReauthorize:] in FacebookSDK(FBSession.o)
  "_ACFacebookAppIdKey", referenced from:
      -[FBSession authorizeUsingSystemAccountStore:accountType:permissions:defaultAudience:isReauthorize:] in FacebookSDK(FBSession.o)
  "_ACAccountTypeIdentifierFacebook", referenced from:
      +[FBSession renewSystemAuthorization] in FacebookSDK(FBSession.o)
  "_ACFacebookAudienceKey", referenced from:
      -[FBSession authorizeUsingSystemAccountStore:accountType:permissions:defaultAudience:isReauthorize:] in FacebookSDK(FBSession.o)
  "_ACFacebookAudienceOnlyMe", referenced from:
      -[FBSession authorizeUsingSystemAccountStore:accountType:permissions:defaultAudience:isReauthorize:] in FacebookSDK(FBSession.o)
  "_ACFacebookPermissionsKey", referenced from:
      -[FBSession authorizeUsingSystemAccountStore:accountType:permissions:defaultAudience:isReauthorize:] in FacebookSDK(FBSession.o)
  "_OBJC_CLASS_$_ASIdentifierManager", referenced from:
      objc-class-ref in FacebookSDK(FBSettings.o)
  "_ACFacebookAudienceEveryone", referenced from:
      -[FBSession authorizeUsingSystemAccountStore:accountType:permissions:defaultAudience:isReauthorize:] in FacebookSDK(FBSession.o)
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Eu achei isso estranho, porque eu uso o mesmo SDK e a mesma configuração com oScrumptious exemplo, E o exemplo está funcionando bem .. Enquanto isso eu tenho esse erro ...

qualquer ideia?