'AS' column-alias beign ignored on outer select

Hi!

Is this the expected behaviour?

 select ID
  , USK_RATING AS USK
  from (
   select ID
    , USK_RATING
   from MAIN_SONY_PS2_GAME
   where ID = 101400
   limit 1
   )
   as PRODUCT_LIST
 limit 1;

   id   | usk_rating
--------+------------
 101400 |
(1 row)

Note the column-header being labeled 'usk_rating', not 'usk'. Obviously
the 'AS' column alias of the outer select is being ignored in the
resultset.

 select ID
  , USK
  from (
   select ID
    , USK_RATING AS USK
   from MAIN_SONY_PS2_GAME
   where ID = 101400
   limit 1
   )
   as PRODUCT_LIST
 limit 1;

   id   | usk
--------+-----
 101400 |
(1 row)

If the column alias is being declared in the subselect, the column alias
is working.

 select version();
                               version
----------------------------------------------------------------------
 PostgreSQL 8.1.0 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.2

Is this working as expected or is this a bug?

Kind regards

   Markus