Forum OpenACS Development: Novice question about typecasting function parameters in postgresql

Hi, I'm trying to get up to snuff on creating apps using openACS and am running into trouble with typecasting postgresql functions. I was just trying to do basically the same thing as the add-edit for the notes application but use a different table with a name and description fields instead of title and body fields. But I get the following message when trying to add a new item:

[06/Sep/2002:11:35:31][1147.4101][-conn1-] Notice: Querying '
      
        select template_product__new(
		  null,
		  '2537',
          'adsf',
          'sdf',
          'template_product',
		  now(),
		  '2537',
		  '192.168.0.1',
		  '7210'
        );'
[06/Sep/2002:11:35:31][1147.4101][-conn1-] Error: Ns_PgExec: result 
status: 7 message: ERROR:  Function 'template_product__new(unknown, 
unknown, unknown, unknown, unknown, timestamptz, unknown, unknown, 
unknown)' does not exist
	Unable to identify a function that satisfies the given 
argument types
	You may need to add explicit typecasts

The actual function is just a tweak of the one in the notes app (i.e.):

create function template_products__new 
(integer,integer,varchar,varchar,varchar,timestamp,integer,varchar,int
eger)
returns integer as '
declare
  p_product_id					alias for $1;       --
 default null
  p_owner_id					alias for $2;       --
 default null
  p_name					alias for $3;
  p_description					alias for $4;
  p_object_type					alias for $5;       --
 default ''template_product''
  p_creation_date				alias for $6;	
	-- default now()
  p_creation_user				alias for $7;	
	-- default null
  p_creation_ip					alias for $8;	
	-- default null
  p_context_id					alias for $9;	
	-- default null
  v_product_id					products.product_id%
TYPE;
begin
	v_product_id := acs_object__new (
		p_product_id,
		p_object_type,
		p_creation_date,
		p_creation_user,
		p_creation_ip,
		p_context_id
	);

	insert into template_products
	  (product_id, owner_id, name, description)
	values
	  (v_product_id, p_owner_id, p_name, p_description);

	PERFORM acs_permission__grant_permission(
          v_product_id,
          p_owner_id,
          ''admin''
    );

I'm sure this is a simple thing but I can't see in the notes app where an explicit typecast is made so am not sure why it's giving me the error message. Any help would be appreciated.