fmgr_info: function 15238119: cache lookup failed

Hi All,

I have a problem with a before update trigger that I was wondering if
someone might be able to give me some help with.

DB version is 7.2. Here is a cut down version of an already simple trigger
and function that is returning the error:

fmgr_info: function 15238119: cache lookup failed

CREATE FUNCTION f_hatyuu_detail( ) RETURNS opaque AS '
BEGIN
raise notice ''f_hatyuu_detail started TG_WHEN= % TG_OP= %'',TG_WHEN,
TG_OP;

if TG_WHEN <> ''BEFORE'' or TG_OP <> ''UPDATE'' then
return null;
end if;

raise notice ''debug 3'';
return new;
raise notice ''debug 4'';
END;
' LANGUAGE 'plpgsql';

drop trigger TG_D_HATYUU_DETAIL_B on D_HATYUU_DETAIL;
create trigger TG_D_HATYUU_DETAIL_B BEFORE update on D_HATYUU_DETAIL for
each row
execute procedure f_hatyuu_detail();

When I do an UPDATE against the table, I get the abovementioned error on the
RETURN NEW; The debug 4 message is not displayed. If I return NULL it
operates as expected (0 rows updated). Did I miss something here?

regards
Iain