AdMob ad doesn't show in the emulator

[D Hagy]

I wrote my first example app, and I try to import in it the Admob ads. I could make that in the Android 2.3.3 graphical layout, that the Ads by Google label is showing instead of com.google...AdView what is showing in every other graphical layout. From 1.6 to 2.2. I don't know why. I thought that my ads will showing only in Android 2.3.3, but wasn't.
Neither in 2.3.3 nor in 2.2 and below. My ad isn't showing in any emulator. But I don't know why, there aren't any error, except what in the 2.2 and lower layouts:

Parser is not a BridgeXmlBlockParser!

The following classes could not be instantiated:
- com.google.ads.AdView
See the Error Log (Window > Show View) for more details.

I don't know what I make bad.

Here is my layout file for this activity:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:background="#fccea8"
  android:screenOrientation ="portrait"
>
    
<TextView
        android:paddingLeft="5dp"
	android:textStyle="bold"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:id="@+id/question"
	android:gravity="center"
	android:textSize="20dp"
	android:textColor="#1f3cb8"
	android:text="???"/>

<Button 
	android:id="@+id/bt1"
	android:gravity="center"
	android:layout_width="fill_parent"
	android:layout_height="wrap_content"
	android:background="@drawable/bt1"
	/>

<Button
	android:id="@+id/bt2"
	android:layout_width="fill_parent"
	android:layout_height="wrap_content"
	android:gravity="center"
	android:background="@drawable/bt2"
	/>

<Button 
	android:id="@+id/bt3"
	android:gravity="center"
	android:layout_width="fill_parent"
	android:layout_height="wrap_content"
	android:background="@drawable/bt3"/>


<Button 
	android:id="@+id/bt4"
	android:layout_width="fill_parent"
	android:layout_height="wrap_content"
	android:gravity="center"
	android:background="@drawable/bt4"/>
	
<Button 
	android:id="@+id/bt5"
	android:layout_width="fill_parent"
	android:layout_height="wrap_content"
	android:gravity="center"
	android:background="@drawable/bt5"/>

 <com.google.ads.AdView android:id="@+id/adView"
                           android:layout_width="wrap_content"
                           android:layout_height="wrap_content"
                           ads:adUnitId="MY_PUBLISHER_CODE"
                           ads:adSize="BANNER" 
                            />
</LinearLayout>

MY_PUBLISHER_CODE = my own publisher code

In the related java (android) class, I imported the

AdView adView = (AdView)this.findViewById(R.id.adView);
	      adView.loadAd(new AdRequest());

code.


In the manifest file, I imported this:

<activity android:name="com.google.ads.AdActivity" 
                  android:configChanges="keyboard|keyboardHidden|orientation"/>

and the internet and network access permission.

Please help me, it's very annoying, that I don't know make this.