PostgreSQL issue: SQLSTATE[22P02]: Invalid text representation

I am running OA-7.x-2.15 on a Linux environment with Apache and PostgreSQL.

Whenever y try to customize a page and select either the Open Atrium or Open Atrium Tasks tabs in the modal, y get a PDOException:

ResponseText: PDOException: SQLSTATE[22P02]: Invalid text representation: 7 ERROR: invalid input syntax for integer: "ipe"
LINE 5: WHERE (base.nid IN ('ipe'))
^: SELECT revision.vid AS vid, base.uid AS uid, revision.title AS title, revision.log AS log, revision.status AS status, revision.comment AS comment, revision.promote AS promote, revision.sticky AS sticky, base.nid AS nid, base.type AS type, base.language AS language, base.created AS created, base.changed AS changed, base.tnid AS tnid, base.translate AS translate, revision.timestamp AS revision_timestamp, revision.uid AS revision_uid
FROM
{node} base
INNER JOIN {node_revision} revision ON revision.vid = base.vid
WHERE (base.nid IN (:db_condition_placeholder_0)) ; Array
(
[:db_condition_placeholder_0] => ipe
)
in DrupalDefaultEntityController->load() (line 191 of /home/juan/dev/sites/openatrium/includes/entity.inc).

In the postgreSQL log, the query is the following:

SELECT revision.vid AS vid, base.uid AS uid, revision.title AS title, revision.log AS log, revision.status AS status, revision.comment AS comment, revision.promote AS promote, revision.sticky AS sticky, base.nid AS nid, base.type AS type, base.language AS language, base.created AS created, base.changed AS changed, base.tnid AS tnid, base.translate AS translate, revision.timestamp AS revision_timestamp, revision.uid AS revision_uid
	FROM 
	node base
	INNER JOIN node_revision revision ON revision.vid = base.vid
	WHERE  (base.nid IN  ('ipe')) 

Anyone has come across the same problem? Any ideas what might bew wrong and hiw tro solve it?

Thanks