BUG #6036: why a REAL should be queried as a string?

The following bug has been logged online:

Bug reference:      6036
Logged by:          jose soares
Email address:      jose.soares@sferacarta.com
PostgreSQL version: 8.4.4
Operating system:   x86_64-pc-linux-gnu
Description:        why a REAL should be queried as a string?
Details:

I'd like to to report this strange behavior, that I think is a bug...

# \d frazione
          Table "public.frazione"
   Column   |  Type   |     Modifiers
------------+---------+--------------------
 id         | integer | not null
 importo    | real    | not null

# update  frazione set importo=0.833 where id=549;
UPDATE 1
# select * from frazione where importo=0.833;
 id | importo
----+---------
(0 rows)

# select * from frazione where importo='0.833';
 id  | importo
-----+----------
 549 |   0.833
(1 rows)