getPopularTags() query fails on Postgresql

When I run:
Doctrine::getTable('TaggableTag')->getPopularTags();
I get: ERROR: column "i2__1" does not exist

The failing query on PostgreSql is:

SELECT t.id AS t_id, t.name AS tname, COUNT(DISTINCT i.id) AS i_0,
(COUNT(DISTINCT i.id)) AS i__1
FROM taggable_tag t
LEFT JOIN cms_model_image_taggable_tag c ON (t.id = c.tag_id)
LEFT JOIN image i ON i.id = c.id
WHERE t.id IN
(SELECT doctrine_subquery_alias.id
FROM
(SELECT DISTINCT t2.id, (COUNT(DISTINCT i2.id)) AS i2__1
FROM taggable_tag t2
LEFT JOIN cms_model_image_taggable_tag c2 ON (t2.id = c2.tag_id)
LEFT JOIN image i2 ON i2.id = c2.id
GROUP BY t2.id HAVING i2__1 > 0
ORDER BY i2__1 DESC LIMIT 10) AS doctrine_subquery_alias)
GROUP BY t.id HAVING i__1 > 0
ORDER BY i__1 DESC

Seems that this just a PostgreSql issue.
On Mysql it runs just fine.

The corrected, working query is:

SELECT t.id AS t_id, t.name AS tname, COUNT(DISTINCT i.id) AS i_0,
(COUNT(DISTINCT i.id)) AS i__1
FROM taggable_tag t
LEFT JOIN cms_model_image_taggable_tag c ON (t.id = c.tag_id)
LEFT JOIN image i ON i.id = c.id
WHERE t.id IN
(SELECT doctrine_subquery_alias.id
FROM
(SELECT DISTINCT t2.id, (COUNT(DISTINCT i2.id)) AS i2__1
FROM taggable_tag t2
LEFT JOIN cms_model_image_taggable_tag c2 ON (t2.id = c2.tag_id)
LEFT JOIN image i2 ON i2.id = c2.id
GROUP BY t2.id HAVING COUNT(DISTINCT i2.id) > 0
ORDER BY i2__1 DESC LIMIT 10) AS doctrine_subquery_alias)
GROUP BY t.id, t.name HAVING COUNT(DISTINCT i.id) > 0
ORDER BY i__1 DESC

For more details, please read the discussion here:
http://stackoverflow.com/questions/2647537/doctrine-sql-query-works-on-mysql-on-postgresql-wont