Android: How to launch background Activity to foreground on Click of received Push Notification using Pending Intent

Question

I am using the following code that I want to run after I receive the Push Notification. This piece of code works fine, if my application is in foreground. But in case the application is in background, then after clicking the push notification, the Activity does not called.

Any ideas, what could be the problem. Please let me know.

public void doOnMessageReceive(String message)
    {   
        try {
            JSONObject response = new JSONObject(message);
            String title = response.getString("title");
            Logger.i("title","title :::"+title);

            NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
            int icon = R.drawable.ic_launcher;
            CharSequence tickerText = "New notification Pending";
            long time = System.currentTimeMillis();

            Notification notification = new Notification(icon,tickerText,time);            
            notification.flags = Notification.DEFAULT_LIGHTS | Notification.DEFAULT_SOUND;
                //| Notification.DEFAULT_VIBRATE |Notification.FLAG_FOREGROUND_SERVICE
                //| Notification.FLAG_HIGH_PRIORITY |Notification.FLAG_ONGOING_EVENT;

            CharSequence contentTitle = "Notifications";
            CharSequence contentText = title;
            Intent notificationIntent = new Intent(this, DetailActivity.class);

            notificationIntent.putExtra(Constants.SELECTED_CATEGORY_KEY, "http://feeds.bbci.co.uk/news/rss.xml");
            notificationIntent.putExtra("guid", title);
            notificationIntent.putExtra(Constants.DISPLAY_ALL_CAT_KEY, true);
            notificationIntent.putExtra(Constants.PARSED_RSS_DATA, RSSDataSingleton.getInstance().getRssDataHM());
        notificationIntent.putExtra(Constants.MAPPED_METADATA_RSS_DATA, RSSDataSingleton.getInstance().getMappedNewsHM());
            PendingIntent contentIntent = PendingIntent.getActivity(this, 99,
                    notificationIntent, Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);

            notification.setLatestEventInfo(getApplicationContext(), contentTitle, contentText, contentIntent);
            mNotificationManager.notify(1, notification);
        } catch (JSONException e) {
            e.printStackTrace();
        }       
    }