Tripled Posts?

I just installed this plugin on WordPress 2.2. Even when it is the only plugin installed, it produces three copies of each post on the front page. In addition, clicking on any category link in the sidebar results in a 404 and some nasty PHP error message:

WordPress database error: [Not unique table/alias: 'wp2_post2cat']
SELECT SQL_CALC_FOUND_ROWS wp2_posts.* FROM wp2_posts LEFT JOIN wp2_post2cat ON (wp2_posts.ID = wp2_post2cat.post_id) LEFT JOIN wp2_categories ON (wp2_post2cat.category_id = wp2_categories.cat_ID) LEFT JOIN wp2_post2cat ON (wp2_posts.ID = wp2_post2cat.post_id) WHERE 1=1 AND category_id IN (15) AND (post_type = 'post' AND (post_status = 'publish' OR post_status = 'private')) AND category_id <> 1 AND category_id <> 2 AND category_id <> 3 AND category_id <> 5 AND category_id <> 7 AND category_id <> 8 AND category_id <> 9 AND category_id <> 10 AND category_id <> 11 AND category_id <> 12 AND category_id <> 13 AND category_id <> 14 AND category_id <> 15 AND category_id <> 16 AND category_id <> 17 AND category_id <> 18 AND category_id <> 19 AND category_id <> 20 AND category_id <> 21 AND category_id <> 22 AND category_id <> 23 GROUP BY wp2_posts.ID ORDER BY post_date DESC LIMIT 0, 10

I hope this can be fixed. In the meantime, I’m going to grab another category management plugin.