error with domains

After creating a new schema and a domain in it, pgAdmin is unable to
display the schema. The code used to create the schema in psql:
jochemd=> select version();
                                version
---------------------------------------------------------------------
  PostgreSQL 7.3.1 on i386-unknown-openbsd3.2, compiled by GCC 2.95.3
(1 row)
jochemd=> CREATE SCHEMA information_schema;
CREATE SCHEMA
jochemd=> GRANT USAGE ON SCHEMA information_schema TO PUBLIC;
GRANT
jochemd=> SET search_path TO information_schema;
SET
jochemd=> CREATE DOMAIN cardinal_number AS integer;
CREATE DOMAIN

In pgAdmin when browsing the information_schema:
An error has occured in pgAdmin II:Main.tvNamespace:

Number: 13
Description: Type mismatch

I'm using pgAdmin version 1.4.12

Jochem