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@yahoo.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?