function that works only once...

Hi list,

I've a strange problem here that someone might know the answer to. I
have a function in plpgsql that works only the first time after
creating (installing) the function. After that I get the following
error:
Fatal - ERROR: pg_class_aclcheck: relation 51755 not found

I've tried to find pg_class_aclcheck in pg_class but it's not there.
Here is my function:

create or replace function display_attributes(varchar) returns varchar as '
declare
classNameVar alias for $1;
query_string text;
tablename varchar(20);
begin
query_string := ''create view the_groupview as select * from
getattribute('' || quote_literal(classNameVar) || '')'';
execute query_string;
select into tablename the_tablename from the_groupview;
drop view the_groupview;
return tablename;
end;'
language 'plpgsql' with (isstrict);

Thanx in advance! :-)

Cheers,
Nick