warning when switching from default language (en) to other language.

Hello,

When I change access my site in a language other than /en/ I get this warning:
user warning: Column 'created' in field list is ambiguous query: SELECT CONCAT(DATE_FORMAT(FROM_UNIXTIME(created), '%Y'),DATE_FORMAT(FROM_UNIXTIME(created), '%v')) AS yearweek, COUNT(CONCAT(DATE_FORMAT(FROM_UNIXTIME(created), '%Y'),DATE_FORMAT(FROM_UNIXTIME(created), '%v'))) AS postcount, DATE_FORMAT(FROM_UNIXTIME(created), '%Y') AS year, DATE_FORMAT(FROM_UNIXTIME(created), '%v') AS week, MONTH(FROM_UNIXTIME(created)) AS month FROM node n LEFT JOIN node i18n ON n.tnid > 0 AND n.tnid = i18n.tnid AND i18n.language = 'eo' WHERE (n.language ='eo' OR n.language ='' OR n.language IS NULL OR n.language = 'en' AND i18n.nid IS NULL) AND ( n.type IN ('blog') AND status = 1 )GROUP BY yearweek ORDER BY yearweek DESC LIMIT 0, 6 in /var/www/vhosts/elopio.net/httpdocs/sites/all/modules/week/week.module on line 119.

To see the warning, enter http://elopio.net/es

Any idea of what might be the problem?

I have i18n module enabled. Please let me know if you need more info to spot the error.

thanks,
pura vida.