I am using a notification where I added an "action" which should start an activity.

I have two main activities: Login Activity and MainActivity. When the LoginActivity is started, it automatically logs in the user (if the user was previously logged in), does some other stuff, and then starts MainActivity. MainActivity is the host for several fragments.

Now when I add LoginActivity like this:

 Intent notificationIntent;
 notificationIntent = new Intent(getActivity(), MainActivity.class);

 notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
         Intent.FLAG_ACTIVITY_SINGLE_TOP);
 PendingIntent intentp =
         PendingIntent.getActivity(getActivity(), 0, notificationIntent, 0);            

    NotificationCompat.Builder nBuilder;
    Uri alarmSound = RingtoneManager
            .getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
    nBuilder = new NotificationCompat.Builder(getActivity())
            .setSmallIcon(R.drawable.ic_launcher)
            .setContentTitle("Smart Share - " + "")
            .setLights(Color.BLUE, 500, 500).setContentText("message")
            .setAutoCancel(true).setTicker("Notification from smartshare")
            .setVibrate(new long[] { 100, 250, 100, 250, 100, 250 })
            .setSound(alarmSound)
            .setAutoCancel(true)
            .setContentIntent(intentp);
    NotificationManager nNotifyMgr = (NotificationManager) getActivity()
            .getSystemService(getActivity().NOTIFICATION_SERVICE);
   Notification not = nBuilder.build();
   nNotifyMgr.notify(2 + 2, not);

Everything works fine. When I put MainActivity into the notificationIntent, a click on the notification does nothing.

How come?

EDIT:

Snippets from my manifest file:

  <activity
        android:name="<packagename>.LoginActivity"
        android:label="@string/app_name"
        android:screenOrientation="portrait"
        android:windowSoftInputMode="stateVisible|adjustResize" >
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <activity
        android:name="<packagename>.MainActivity"
        android:label="@string/tab_title_mapview"
        android:screenOrientation="portrait">
    </activity>

try this :

PendingIntent contentIntent = PendingIntent.getActivity(getActivity(),0,PendingIntent.FLAG_UPDATE_CURRENT| PendingIntent.FLAG_ONE_SHOT);