PostgreSQL incompatibility: use ORDER BY <field>, <field> not ORDER BY <field> AND <field>

We installed Sequenced Newsletter recently, and have been getting these error messages:

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pg_query() [function.pg-query]: Query failed: ERROR: argument of AND must be type boolean, not type character varying LINE 1: ...S su WHERE s.nid=n.nid and s.sid=su.snid ORDER BY mail AND d... ^ in /home/friendsofqola/public_html/includes/database.pgsql.inc on line 138.

query: SELECT sid, title, date_spooled, mail FROM sequenced_newsletter as s, node as n, simplenews_subscriptions AS su WHERE s.nid=n.nid and s.sid=su.snid ORDER BY mail AND date_spooled DESC in /home/friendsofqola/public_html/sites/all/modules/sequenced_newsletter/sequenced_newsletter.module on line 29.

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The problem is that line 29 uses 'ORDER BY mail AND date_spooled DESC' instead of 'ORDER BY mail, date_spooled DESC'. I'm surprised that it works on MySQL (I so far can't find use of AND in this way in the MySQL documentation). Patch to follow.