named_scope and duplicate sql conditions

suppose we got two models: category and article.
category has_many articles, article belongs_to category

article has a named_scope defined by
named_scope :online, :conditions => {:state => 2}

in the controller i want to search for online articles that belongs to
a given category. i tried this query:
@category.articles.online.find(params[:id))
it works, but it duplicates the condition about the category in the
generated SQL:
SELECT * FROM "articles" WHERE ("articles"."id" = 6 AND
("articles".category_id = 1)) AND (("articles"."state" = 2) AND
("articles".category_id = 1))

am i missing something?

I've run across this before - there's a ticket on Lighthouse about it,
but it's eluding me at the moment.

If you're really feeling adventurous, you can try your hand at fixing
it. I don't get the sense that it's a super-high priority, given that
any decent query optimizer on the DB side is going to figure out that
the condition is duplicated and drop it.

--Matt Jones