You remember the post How to get a page/post content, don’t you? Then, we may get the page/post content by:

function getPageBySlug( $slug ) 
  $objectPost = get_page_by_path($slug);
  return apply_filters("the_content",$objectPost->post_content);

As you can see from the code above, we used get_page_by_path() function instead get_page_by_title() function, because some plugin ( like qTranslate )  could change the content on the database. In fact, the get_page_by_title() function gets a content of a page through a database SELECT statement:

function get_page_by_title($page_title, $output = OBJECT, $post_type = 'page' ) {
  global $wpdb;
  $page = $wpdb->get_var( $wpdb->prepare( "SELECT ID FROM $wpdb->posts
WHERE post_title = %s AND post_type= %s", $page_title, $post_type ) );
  if ( $page )
    return get_page($page, $output);

  return null;

So, if for some reason the title has been changed then the get_page_by_title() function doesn’t work properly. The  get_page_by_path() function uses the slug. Further, the get_page_by_path() function works with private pages as well.