[Plugin: ShareThis] Buttons not appearing

Buttons are not showing when I use the get_content() since I have a custom script to apply ‘Read more’ links to individual posts.

Only when the function defaults to the_excerpt(), do the buttons show up.

Is there a way to make it show the buttons in this case?

My function:

function show_content_before_more_tag($post){
  global $more;
  $more = 0;

  // checks to see if the is a 'more' tag in post
  // show if theres is
  // truncate post if there is not
  $ismore = @strpos($post -> post_content, '<!--more');
  if($ismore){
    $content_arr = get_extended( get_the_content() );
    echo $content_arr['main'];
  } else {
    the_excerpt();
  }
}

// Replaces the excerpt "more" text by a link
function new_excerpt_more($more) {
  global $post;
  return '<a class="moretag" href="'. get_permalink($post->ID) . '"> Read more.</a>';
}
add_filter('excerpt_more', 'new_excerpt_more');