Description:
------------
when I used pdo for the sql "select round(863521.777777778, 2) as a", it gets 
wrong result 863521.780000001

Test script:
---------------
<?php
$db = new PDO("sqlite:../test.s3db");
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$st = $db->query('select round(863521.777777778, 2) as a');
$data = $st->fetchAll();
print_r($data);

$st = $db->query('select round(372366.577777778, 2) as a');
$data = $st->fetchAll();
print_r($data);


Expected result:
----------------
Array
(
    [0] => Array
        (
            [a] => 863521.780000001
            [0] => 863521.780000001
        )

)
Array
(
    [0] => Array
        (
            [a] => 372366.58
            [0] => 372366.58
        )

)