Forum OpenACS Q&A: xowiki V0.118 - exception NSINT, Query returned more than one row

I was able to see /xowiki/index exactly once. All additional requests to either /xowiki/index or xowiki/admin/ would result in the following error:

Database operation "0or1row" failed
(exception NSINT, "Query returned more than one row.")
(Status of PQexec call: none; PQexec returned null pointer)
SQL: select n.object_type,o.creation_user,o.creation_date,i.publish_status,n.last_modified,o.package_id,n.page_order,n.creator,n.ppage_id,n.page_id,n.object_id,n.description,n.xowiki_object_id,n.data AS text,n.title,n.nls_language,i.name,n.mime_type,n.title,n.revision_id,n.item_id,n.publish_date,n.creation_user as modifying_user, i.parent_id from xowiki_objecti n, cr_items i, acs_objects o where i.item_id = 617212 and n.xowiki_object_id = coalesce(i.live_revision, i.latest_revision) and o.object_id = i.item_id

while executing
"ns_pg_bind 0or1row nsdb0 { select n.object_type,o.creation_user,o.creation_date,i.publish_status,n.last_modified,o.package_id,n.page_order,n.creator,n..."
("uplevel" body line 1)
invoked from within
"uplevel $ulevel [list ns_pg_bind $type $db $sql]"
("postgresql" arm line 2)
invoked from within

View 'xowiki_objecti' returns two identical records. Any clues where to start diggin'?

Thanks in advance
Klaus

select * from cr_text (make sure it shows more than one row, otherwise the problem lies somewhere else)

alter table cr_text disable trigger cr_text_tr;
delete from cr_text;
insert into cr_text (text_data) values ('');
alter table cr_text enable trigger cr_text_tr;