If a user's "most active topic" is on the moderation queue, it still shows up, even if the user viewing the profile is not permitted to see topics on the queue.

	// Obtain active topic

	$sql = 'SELECT topic_id, COUNT(post_id) AS num_posts

		FROM ' . POSTS_TABLE . '

		WHERE poster_id = ' . $userdata['user_id'] . "

			AND post_postcount = 1

			$forum_sql

		GROUP BY topic_id

		ORDER BY num_posts DESC";

The query ignores the post_approved column entirely.

tbh, I'm not sure that I would fix this. I'd have to look at the query optimizer output, these activity queries are nasty enough.