addView FILL_PARENT not working
===

I want to put a layout into another one via layoutInflater.

Here's the main_layout.xml file:

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <ImageView
        android:id="@+id/ads_image_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:src="@drawable/ic_launcher" />

    <RelativeLayout
        android:id="@+id/host_layout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/navigation_buttons_layout"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/ads_image_view" >
    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/navigation_buttons_layout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true" >


        <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentRight="true"
            android:layout_alignParentTop="true"
            android:text="Button" />
        
    </RelativeLayout>

</RelativeLayout>
and here's the vitrin_layout.xml file:

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <ImageView
        android:id="@+id/ads_image_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:src="@drawable/ic_launcher" />

    <RelativeLayout
        android:id="@+id/host_layout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/navigation_buttons_layout"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/ads_image_view" >
    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/navigation_buttons_layout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true" >


        <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentRight="true"
            android:layout_alignParentTop="true"
            android:text="Button" />
        
    </RelativeLayout>

</RelativeLayout>
and finally the onCreate method for my main activity:

    @Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main_layout);
		ViewGroup parent = (ViewGroup) findViewById(R.id.host_layout);
		View view = LayoutInflater.from(getBaseContext()).inflate(
				R.layout.vitrin_layout, null);
		parent.addView(view, LayoutParams.FILL_PARENT);

		setTitle(getString(R.string.title_activity_vitrin));
	}

The problem is that the vitrin_layout, does not fit into its parent(host_layout); although I've set fill_parent where ever I could!
<br/>I can't figure out why.