Map shows marker but doesn't show real map in background
<p>I have map in m android app but it doesn't work well. I spent last two hours looking in code line by line but I don't know what is the problem. I done all like in tutorial <a href="http://mobiforge.com/developing/story/using-google-maps-android" rel="nofollow">http://mobiforge.com/developing/story/using-google-maps-android</a>. I set in manifest uses google maps. Map shows marker, doesn't show map ( instead in background is grid lines), zoom controls disappear after few seconds and not come back. What can be a problem ?
<img src="http://i.stack.imgur.com/3pcWj.png" alt="alt text"></p>

<p>This is activity class.</p>

<pre><code>package com.roomate.www;
import java.util.List;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.MapView.LayoutParams;  
import com.google.android.maps.Overlay;

import android.view.View;
import android.widget.LinearLayout;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Point;
import android.os.Bundle;
import android.util.Log;

public class Location extends MapActivity{
 MapView mapView; 
    MapController mc;
    GeoPoint p;

    class MapOverlay extends com.google.android.maps.Overlay
    {
        @Override
        public boolean draw(Canvas canvas, MapView mapView, 
        boolean shadow, long when) 
        {
            super.draw(canvas, mapView, shadow);                   

            //---translate the GeoPoint to screen pixels---
            Point screenPts = new Point();
            mapView.getProjection().toPixels(p, screenPts);

            //---add the marker---
            Bitmap bmp = BitmapFactory.decodeResource(
                getResources(), R.drawable.marker);            
            canvas.drawBitmap(bmp, screenPts.x, screenPts.y-50, null);         
            return true;
        }
    } 



 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.map_result);

  mapView = (MapView) findViewById(R.id.mapView);
  mapView.setStreetView(true);
        LinearLayout zoomLayout = (LinearLayout)findViewById(R.id.zoom);  
        View zoomView = mapView.getZoomControls(); 

        zoomLayout.addView(zoomView, 
            new LinearLayout.LayoutParams(
                LayoutParams.WRAP_CONTENT, 
                LayoutParams.WRAP_CONTENT)); 
        mapView.displayZoomControls(true);

        mc = mapView.getController();
        String coordinates[] = {"1.352566007", "103.78921587"};
        double lat = Double.parseDouble(coordinates[0]);
        double lng = Double.parseDouble(coordinates[1]);

        p = new GeoPoint(
            (int) (lat * 1E6), 
            (int) (lng * 1E6));

        mc.animateTo(p);
        mc.setZoom(17); 
        MapOverlay mapOverlay = new MapOverlay();
        List&lt;Overlay&gt; listOfOverlays = mapView.getOverlays();
        listOfOverlays.clear();
        listOfOverlays.add(mapOverlay);        

        mapView.invalidate();

 }
 @Override
    protected boolean isRouteDisplayed() {
        return false;
    }
}
</code></pre>

<p>This is layout for map.
    
    </p>

<pre><code>&lt;LinearLayout
    android:orientation="horizontal"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  &gt;
  &lt;LinearLayout
  android:layout_gravity="left"
  android:gravity="left"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"&gt;
  &lt;ImageButton
   android:id="@+id/imbReturnMap"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:fitsSystemWindows="true"
   android:src="@drawable/close"
   android:layout_gravity="left"&gt;
  &lt;/ImageButton&gt;
  &lt;/LinearLayout&gt;

  &lt;LinearLayout
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:gravity="right"
  android:layout_gravity="right"&gt;
  &lt;ImageButton
   android:id="@+id/imbCloseM"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:fitsSystemWindows="true"
   android:src="@drawable/close"
   android:layout_gravity="right"&gt;
  &lt;/ImageButton&gt;
  &lt;/LinearLayout&gt;  

 &lt;/LinearLayout&gt;

&lt;RelativeLayout 
    android:id="@+id/mainlayout"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" &gt;
    &lt;com.google.android.maps.MapView
       android:id="@+id/mapView"
                 android:layout_width="fill_parent"
                 android:layout_height="fill_parent"
                 android:apiKey="0WR3Cl0evv0U6G2xH9ZnvEFYbDiSDUu_GRovTUQ"
                 /&gt;
     &lt;LinearLayout android:id="@+id/zoom" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:layout_alignParentBottom="true" 
        android:layout_centerHorizontal="true" 
        /&gt; 

&lt;/RelativeLayout&gt;
&lt;/LinearLayout&gt;
</code></pre>
