Android : Androiod notification set and update

I'm setting a notification (which works 100% fine).

    int notifyID=5;
    NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getApplicationContext())
                .setSmallIcon("A title")
                .setContentTitle("My content words")
                .setContentText(R.drawable.whatever);

    NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    mNotificationManager.notify(notifyID, mBuilder.build());

I then start an alarm manager, which goes off, runs my WakefulBroadcastReceiver class where I attempt to update the information in the notification. I don't care if the notification has to flash when it updates or anything, I just want it to update the information.

    NotificationManager mNotificationManager = (NotificationManager) mContext.getSystemService(Context.NOTIFICATION_SERVICE);

    NotificationCompat.Builder mNotifyBuilder = new NotificationCompat.Builder(mContext)
        .setContentTitle("Any new title")
        .setContentText("Any new content");

    mNotificationManager.notify(
        notifyID,
        mNotifyBuilder.build());

Calling this removes the notificaiton