Query Problem

Hi There !!
My turn to ask for some help ;)

a friend of mine has a problem with this query:

SELECT zblog_category.catname, zblog_entry.entry_id,
zblog_entry.entrytext, zblog_entry.entrytitle,
zblog_entry.timestamp_creation, zblog_user.username,
COUNT(zblog_comment.comment_id) AS comment_amount FROM zblog_comment
RIGHT JOIN (zblog_user INNER JOIN (zblog_entry INNER JOIN
zblog_category ON (zblog_category.cat_id = zblog_entry.id_cat)) ON
(zblog_entry.id_user = zblog_user.user_id)) ON (zblog_comment.id_entry
= zblog_entry.entry_id) WHERE zblog_comment.id_entry =
zblog_entry.entry_id AND zblog_category.cat_id = zblog_entry.id_cat AND
zblog_user.user_id = zblog_entry.id_user AND
zblog_entry.timestamp_creation >= 1 AND zblog_entry.timestamp_creation
< 999999999999 GROUP BY zblog_entry.entry_id ORDER BY
zblog_entry.timestamp_creation DESC

The error we are getting is this

ERROR: column "zblog_category.catname" must appear in the GROUP BY
clause or be used in an aggregate function

any idea? we kept trying for hours to no avail *sigh* :'(

thanks in advance for your time and attention!

Regards,
David Costa, PHP-PostgreSQL Advocacy team http://dotgeek.org
david at postgresql ddoot org gurugeek att php dot net
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