BUG #5419: Default parameters in PLPGSQL functions skipping every other value in pgAdmin view

The following bug has been logged online:

Bug reference: 5419
Logged by: Cris Pond
Email address: cpondwork(at)yahoo(dot)com
PostgreSQL version: 8.4.2
Operating system: Ubuntu 9.10 kernel linux 2.6.31-20-generic
Description: Default parameters in PLPGSQL functions skipping every
other value in pgAdmin view
Details:

I define a function as such:

create or replace function _users (
_mode varchar (1) default null,
_id int4 default null,
_username varchar default null,
_encryptedpassword varchar default null,
_accountenabled bool default null,
_administrationenabled bool default null,
...

It compiles and functions correctly.

When I go to the pgAdmin interface to view the function, it skips the
default value for every other parameter! Like so:

CREATE OR REPLACE FUNCTION _users(
_mode character varying DEFAULT NULL::character varying,
_id integer,
_username character varying DEFAULT NULL::integer,
_password character varying,
_accountenabled boolean DEFAULT NULL::character varying,
_administrationenabled boolean,

...

You can see the types are mismatched, and the function won't compile.

Oddly enough, this error does not occur in the M$ version of Postgres.

Am I doing something wrong, or is this really a bug?