Inherit Superuser Role Help

What am I missing here?

postgres=> SELECT current_user;
current_user
--------------
carlos
(1 row)

postgres=> CREATE DATABASE carlosdb;
ERROR: permission denied to create database

postgres=> \du
List of roles
Role name | Attributes
| Member of
-----------+--------------------------------------------------------------+-----------
carlos |
| {dba}
chris |
| {web}
dba | Superuser, Create role, Create DB, Cannot login, Replication | {}
postgres | Superuser, Create role, Create DB, Replication | {}
web | Cannot login | {}

Shouldn't 'carlos' be a superuser based on him being a member of a
role which has createdb and superuser rights granted to it?

--
Carlos Mennens