Description:
------------
On certain data preg_replace() returns empty string. The code below works correctly on PHP 5.1.6

Reproduce code:
---------------
<?php

$data = file_get_contents('src.sql');
echo strlen($data).'<br>';
$data = preg_replace("#INSERT\\sINTO([\\s\\S]*?)INSERT\\sINTO#", "\$DELTA_SCRIPT[] = 'INSERT INTO\\1'; \$DELTA_SCRIPT[] = 'INSERT INTO", $data);
$data = preg_replace("#CREATE\\sTABLE([\\s\\S]*?)[^']INSERT\\sINTO#", "CREATE TABLE \\1 \$DELTA_SCRIPT[] = 'INSERT INTO", $data);
echo strlen($data); //returns 0 here

?>

Expected result:
----------------
Return whatever but empty string.

Actual result:
--------------
Returns empty string.