11128.1 != 11128.1

Hi,

I have one table defined as follows:

CREATE TABLE bank (
....
incr FLOAT NOT NULL DEFAULT 0.0 ,
....) ;

When I make query

SELECT * FROM bank WHERE incr = 11128.1;

it returns no result although at least one row satisfy this condition.
I can get result only with modified query

SELECT * FROM bank WHERE round(incr,1) = round(11128.1,1);

Is there some error in libc,OS or postgres? I have tried
to dump-destroy-create-restore whole database and
it looked good but after few hours I got into trouble again.

I run 6.5.1 version, compiled with gcc 2.95.1 (libc-2.1.2)
on Debian Linux 2.2.11.

Radek Kanovsky, rk(at)uh(dot)cz