Drop-Down Post List Plugin duplicate posts

I’m using v1.33 of this plugin on WordPress 2.9.2 to create a dropdown “jump” list of recent blog posts in my sidebar:

https://www.dagondesign.com/articles/drop-down-post-list-plugin-for-wordpress/

It appears that, when a post is filed under more than one category, it will appear in the dropdown’s list once for each category. Has anyone else had this issue or encountered a fix?

I don’t know much about PHP or SQL, but I’m guessing there’s something amiss with this part of the code (lines 238-256 in dd-drop-down-post-list.php):

$cat_sel_code = ' ';
		if (!$all_cats) {
			$cat_sel_code = " AND {$table_prefix}term_taxonomy.term_id = {$catID} ";
		}

		$post_list = (array)$wpdb->get_results("
			SELECT ID,
				post_title,
				post_date
			FROM {$table_prefix}posts, {$table_prefix}term_relationships, {$table_prefix}term_taxonomy
			WHERE {$table_prefix}posts.ID = {$table_prefix}term_relationships.object_id
			AND {$table_prefix}term_relationships.term_taxonomy_id = {$table_prefix}term_taxonomy.term_taxonomy_id
			AND {$table_prefix}term_taxonomy.taxonomy = 'category'
			{$cat_sel_code}
			AND post_status = 'publish'
			AND post_type != 'page'
			{$sort_code}
			{$limit_code}
		");