Youtube API "An error occurred while initializing the YouTube player."

I'm using Youtube API to have simple playerView on my application. I did what the API said to do but I keep getting "application is stopped" message. I don't really know the exact english phrase since I'm using a Korean Phone. Hope that's the right phrase in English.

I put Youtubeandroidplayerapi.jar in libs and built the path and have the unnecessary components in library.

Here is Menu.java.

package com.hobak.sci;

import com.hobak.sci.DeveloperKey;
import com.hobak.sci.R;
import com.google.android.youtube.player.YouTubeBaseActivity;
import com.google.android.youtube.player.YouTubeInitializationResult;
import com.google.android.youtube.player.YouTubePlayer;
import com.google.android.youtube.player.YouTubePlayer.Provider;
import com.google.android.youtube.player.YouTubePlayerView;
import android.os.Bundle;

public class Menu extends YouTubeBaseActivity implements
    YouTubePlayer.OnInitializedListener {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.menu);

        YouTubePlayerView youTubeView = (YouTubePlayerView) findViewById(R.id.youtube_view);
    youTubeView.initialize(DeveloperKey.DEVELOPER_KEY, this);
    }

    @Override
    public void onInitializationSuccess(YouTubePlayer.Provider provider,
        YouTubePlayer player, boolean wasRestored) {
    if (!wasRestored) {
        player.cueVideo("2LHv1FPd1Ec");
    }
}

protected YouTubePlayer.Provider getYouTubePlayerProvider() {
    return (YouTubePlayerView) findViewById(R.id.youtube_view);
}

@Override
public void onInitializationFailure(Provider arg0,
        YouTubeInitializationResult arg1) {
    // TODO Auto-generated method stub

}

}

and here is my xml file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_h