Error while invoking link 'recent posts'

I have the 'tracker' module enabled and just clicked on the link 'recent posts' (http://www.myhost.tld/tracker).
I'm getting the following error message:

query: SELECT node.nid, node_comment_statistics.last_comment_timestamp AS node_comment_statistics_last_comment_timestamp_last_comment_timestamp, node.type AS node_type, node.title AS node_title, node.changed AS node_changed, users.name AS users_name, users.uid AS users_uid, node_comment_statistics.comment_count AS node_comment_statistics_comment_count, node_comment_statistics.last_comment_timestamp AS node_comment_statistics_last_comment_timestamp FROM node node LEFT JOIN node_comment_statistics node_comment_statistics ON node.nid = node_comment_statistics.nid INNER JOIN users users ON node.uid = users.uid LEFT JOIN localizernode loc ON loc.nid=node.nid LEFT JOIN(select 2 weight, 'de' language union select -100 weight, 'en' language union select 3 weight, 'fr' language union select 4 weight, 'es' language) lanw ON lanw.language=loc.language LEFT JOIN (select pid, MIN(weight) minweight from localizernode loc2 inner join (select 2 weight, 'de' language union select -100 weight, 'en' language union select 3 weight, 'fr' language union select 4 weight, 'es' language) lanw2 on lanw2.language=loc2.language group by pid) loc1 ON loc.pid=loc1.pid WHERE (lanw.weight=loc1.minweight) AND ( (node.status = '1') ) ORDER BY node_comment_statistics_last_comment_timestamp_last_comment_timestamp DESC LIMIT 25 OFFSET 0 in D:\Websites\Stiegele\includes\database.pgsql.inc on line 144.

pg_query() [function.pg-query]: Query failed: ERROR: syntax error at or near "weight" LINE 1: ...ernode loc ON loc.nid=node.nid LEFT JOIN(select 2 weight, 'd... ^ in D:\Websites\Stiegele\includes\database.pgsql.inc on line 125.

query: SELECT count(node.nid) FROM node node LEFT JOIN node_comment_statistics node_comment_statistics ON node.nid = node_comment_statistics.nid INNER JOIN users users ON node.uid = users.uid LEFT JOIN localizernode loc ON loc.nid=node.nid LEFT JOIN(select 2 weight, 'de' language union select -100 weight, 'en' language union select 3 weight, 'fr' language union select 4 weight, 'es' language) lanw ON lanw.language=loc.language LEFT JOIN (select pid, MIN(weight) minweight from localizernode loc2 inner join (select 2 weight, 'de' language union select -100 weight, 'en' language union select 3 weight, 'fr' language union select 4 weight, 'es' language) lanw2 on lanw2.language=loc2.language group by pid) loc1 ON loc.pid=loc1.pid WHERE (lanw.weight=loc1.minweight) AND ( (node.status = '1') ) in D:\Websites\Stiegele\includes\database.pgsql.inc on line 144.

pg_query() [function.pg-query]: Query failed: ERROR: syntax error at or near "weight" LINE 1: ...ernode loc ON loc.nid=node.nid LEFT JOIN(select 2 weight, 'd... ^ in D:\Websites\Stiegele\includes\database.pgsql.inc on line 125.