'real' strange problem in 7.1.3

I have a database in PG 7.1.3 with the following schema:

db02=# \d ellipse                 Table "ellipse"       Attribute         |     Type     | Modifier 
--------------------------+--------------+----------subject                  | text         | arm
|character(1) | rep                      | integer      | exp_date                 | date         | exp_time
    | time         | success                  | integer      | figure_radius            | integer      | tube_radius
         | integer      | cursor_radius            | integer      | direction                | integer      |
ellipse_ratio           | real         | exag_ratio               | real         | exag_start               | integer
  | exag_end                 | integer      | rotation_angle           | real         | min_inter_trial_interval |
integer     | 
 
Index: pkellipse

If I try the command:
db02=# select distinct arm from ellipse where exag_ratio = 1.0;arm 
-----LR
(2 rows)

which is correct.

Now I try the same command with a different 'real' field:
db02=# select distinct arm from ellipse where ellipse_ratio = 1.8;arm 
-----
(0 rows)

BUT, if I put the value in quotes (as if it were a string), I get:

db02=# select distinct arm from ellipse where ellipse_ratio = '1.8';arm 
-----LR
(2 rows)

which is correct.

This variable ellipse_ratio seems to be the only one of type 'real'
that requires me to use quotes (which doesn't really make sense since
it's not a character or string anyway). exag_ratio and rotation_angle
behave as I would expect a real-typed variable to behave.

db02=# select distinct exag_ratio, ellipse_ratio, rotation_angle from
ellipse;exag_ratio | ellipse_ratio | rotation_angle 
------------+---------------+----------------         1 |          0.56 |              0         1 |           1.8 |
         0
 
(2 rows)



Has anyone seen this behavior before? Perhaps, I'm doing something
wrong here or thinking of this all wrong?

Thanks.
-Tony Reina

Welcome to psql, the PostgreSQL interactive terminal.

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db02=# select version();                          version                           
-------------------------------------------------------------PostgreSQL 7.1.3 on i686-pc-linux-gnu, compiled by GCC
2.96
(1 row)

PG server is RH Linux 7.1 (Seawolf), PIII 400 MHz
Vacuum verbose analyze performed just prior to the searches listed
just to be sure.