By comparing backups, I found
CREATE CONSTRAINT TRIGGER "<unnamed>" AFTER INSERT OR UPDATE ON "person" NOT DEFERRABLE INITIALLY IMMEDIATE FOR EACH
ROWEXECUTE PROCEDURE "RI_FKey_check_ins" ('<unnamed>', 'person', 'subject', 'UNSPECIFIED', 'subjectid', 'id');
Don't know where that came from, but probably operator error.. There isn't
an easy way of scrubbing an unnamed trigger is there? (I dump/edit/reloaded)
Cheers,
Patrick