¿Cómo puedo explicar mi problema?

Tengo una aplicación que usa pestañas (por intenciones, no vistas). He implementado la navegación dentro de cada vista sin problemas, pero necesito iniciar el reproductor de video desde ListView dentro de una de las Actividades en pantalla completa y en modo horizontal (sin pestañas). Pero cuando quiero vivir el reproductor, (ya sea presionando hacia atrás o llamando a terminar ();), mi aplicación se cierra (sin excepciones en LogCat) y regreso a la pantalla principal. Entonces, lo que necesito es que cuando salga de la Actividad de pantalla completa (iniciada para el reproductor) es volver a mi aplicación, con las pestañas.

Aquí está mi código:

//Main activity : 

package com.ccn;


import android.app.TabActivity;
import android.content.Intent;
import android.content.res.Resources;
import android.os.Bundle;
import android.widget.TabHost;

public class CCNMain extends TabActivity {
    public static TabHost tabHost;
    static CCNMain  myActivity = null;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        myActivity = this;

        Resources res = getResources();
        tabHost = getTabHost();
        TabHost.TabSpec spec; // reusable tabspec for each tab
        Intent intent;

        intent = new Intent().setClass(this, NewsGroup.class);
        spec = tabHost.newTabSpec("nnews")
        .setIndicator("A la une",res.getDrawable(R.drawable.home))
        .setContent(intent);
        tabHost.addTab(spec);

        /*intent = new Intent().setClass(this, ArticlesGroup.class);
        spec = tabHost.newTabSpec("aarticles")
        .setIndicator("Articles",res.getDrawable(R.drawable.articles))
        .setContent(intent);
        tabHost.addTab(spec);*/

        intent = new Intent().setClass(getApplicationContext(), ContactGroup.class);
        spec = tabHost.newTabSpec("vvideos")
        .setIndicator("Vidéos",res.getDrawable(R.drawable.video))
        .setContent(intent);
        tabHost.addTab(spec);

        intent = new Intent().setClass(getApplicationContext(), ContactGroup.class);
        spec = tabHost.newTabSpec("ccontact")
        .setIndicator("Contact",res.getDrawable(R.drawable.contact))
        .setContent(intent);
        tabHost.addTab(spec);

        tabHost.setCurrentTab(0);
    }
}

//ContactGroup : 
package com.ccn;

import java.util.ArrayList;


import android.app.ActivityGroup;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;

public class ContactGroup extends ActivityGroup {
    // Keep this in a static variable to make it accessible for all the nested activities, lets them manipulate the view  
    public static ContactGroup groupContact;  

        // Need to keep track of the history if you want the back-button to work properly, don't use this if your activities requires a lot of memory.  
    private ArrayList<View> history;  
  @Override
    protected void onCreate(Bundle savedInstanceState) {  
          super.onCreate(savedInstanceState);  
          this.history = new ArrayList<View>();  
          groupContact = this;  

              // Start the root activity within the group and get its view  
          View view = getLocalActivityManager().startActivity("idHoraireActivity", new  
                                            Intent(this,ContactActivity.class)  
                                            .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP))  
                                            .getDecorView();  

              // Replace the view of this ActivityGroup  
          replaceView(view);  

      , }  

    public void replaceView(View v) {  
                // Adds the old one to history  
        history.add(v);  
                // Changes this Groups View to the new View.  
        setContentView(v);  
    }  

    public void back() {  
        if(history.size() > 1) {  
            history.remove(history.size()-1);  
            setContentView(history.get(history.size()-1));  
        }else {  
            finish();  
        }  
    }  
    //@Override  
    public void onBackPressed() {  
        ContactGroup.groupContact.back();  
        return;  
    }

}

//ContactActivity:
package com.ccn;

import java.io.IOException;

import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.MediaController;
import android.widget.Toast;
import android.widget.VideoView;

public class ContactActivity extends Activity {
    static ContactActivity bidule = null;
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.videos);
        bidule = this;
        Button btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent i = new Intent();
                i.setClass(getApplicationContext(), videoPlayerActivity.class);
                //i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                bidule.startActivity(i);
                ContactActivity.this.startActivityForResult(i, 0);
            }
        });

    }

}

//VideoPlayerActivity:
package com.ccn;

import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.MediaController;
import android.widget.VideoView;


public class videoPlayerActivity extends Activity {

    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.videos);


        //the VideoView will hold the video
        String url = // Video url;

        Button btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                finish();
            }
        });
    }


}

Y aquí mi Manifiesto:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.ccn"
      android:versionCode="1"
      android:versionName="1.0">
<uses-permission android:name="android.permission.INTERNET"></uses-permission>


    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".CCNMain"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name="ArticlesGroup"></activity>
        <activity android:name="ContactGroup"></activity>
        <activity android:name="NewsGroup"></activity>
        <activity android:name="NewsActivity"></activity>
        <activity android:name="ArticlesAvtivity"></activity>
        <activity android:name="ContactActivity"></activity>
        <activity android:name="videoPlayerActivity" android:theme="@android:style/Theme.NoTitleBar.Fullscreen" android:screenOrientation="landscape"></activity>

    </application>
</manifest>

Gracias por tu ayuda. Mi suposición: tiene que ver con donde llamo a las banderas startActivity e Intent. ¿Qué piensas