Ihre Inhalte müssen einen TabHost, deren id-Attribut 'android.R.id.tabhost'

Ich habe ein problem:

Java-Code

public class VisualizzaListaActivity extends TabActivity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    TabHost tabHost = getTabHost();  //The activity TabHost
    TabHost.TabSpec spec;  //Reusable TabSpec for each tab
    Intent intent;  //Reusable Intent for each tab

    //Create an Intent to launch an Activity for the tab (to be reused)
    intent = new Intent().setClass(this, DaAcquistareActivity.class);

    //Initialize a TabSpec for each tab and add it to the TabHost
    spec = tabHost.newTabSpec("daAcquistare").setIndicator("Da Acquistare").setContent(intent);
    tabHost.addTab(spec);

    //Do the same for the other tabs
    intent = new Intent().setClass(this, AcquistatiActivity.class);
    spec = tabHost.newTabSpec("acquistati").setIndicator("Acquistati").setContent(intent);
    tabHost.addTab(spec);

    tabHost.setCurrentTab(0);
}

}

XML-code

<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/tabhost"   <-------------- It's tabhost -.-"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

<LinearLayout
   android:orientation="vertical"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:padding="5dp">
    <TabWidget
       android:id="@android:id/tabs"
       android:layout_width="fill_parent"
       android:layout_height="wrap_content" />
    <FrameLayout
       android:id="@android:id/tabcontent"
       android:layout_width="fill_parent"
       android:layout_height="fill_parent"
       android:padding="5dp" />
</LinearLayout>
</TabHost>

Und LogCat

12-16 15:26:22.519: E/AndroidRuntime(8262): java.lang.RuntimeException: Unable to start activity ComponentInfo{android.smile.matteo.spesaPRO/android.smile.matteo.spesaPRO.VisualizzaListaActivity}: java.lang.RuntimeException: Your content must have a TabHost whose id attribute is 'android.R.id.tabhost'             
12-16 15:26:22.519: E/AndroidRuntime(8262): Caused by: java.lang.RuntimeException: Your content must have a TabHost whose id attribute is 'android.R.id.tabhost'
12-16 15:26:22.519: E/AndroidRuntime(8262):         at android.smile.matteo.spesaPRO.VisualizzaListaActivity.onCreate(VisualizzaListaActivity.java:13)

Problem

Kann mir jemand sagen, warum es ist, sagt

Ihre Inhalte müssen einen TabHost, deren id-Attribut 'android.R.id.tabhost'

wenn die android:id = @android:id/tabhost?