Referencing named attribute in where clause doesn't work with 7.1.2?

Hi, this is my first post to this list so please...
I have problems getting this query to work, any ideas?

select article.title_text_key,
(select on_text.text_value from on_text where
on_text.text_key = title_text_key
AND NOT title_text_key is NULL
AND on_text.lang_id = (select code.id from code, code_group where
code.code_group_id = code_group.id
AND code_group.description = 'lang' AND code.code_key = 'lang.NO'
)
)
as title_text_value from article where NOT title_text_value is NULL;

ERROR: Attribute 'title_text_value' not found

Issuing the same query without the where-clause does work tho, but
return tupples with null in them which I don't want.

--
Andreas Joseph Krogh <andreak(at)officenet(dot)no>