// looping through all rows and adding to list
    if (cursor.moveToFirst()) {
        do {
            String contactname0 = ContactsHelper.getContactName(context, cursor.getString(0));
            String contactname2 = ContactsHelper.getContactName(context, cursor.getString(2));
            List.add(contactname0+": "+contactname2);
        } while (cursor.moveToNext());
    }
    cursor.close();
    return List;
}

08-03 17:10:56.281: E/AndroidRuntime(6301): java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Object.toString()' on a null object reference