Description:
------------
Driver version: git commit id 9668027

PHP version: 5.2.6-3ubuntu4.1 (comes with Ubuntu Jaunty).

Problem: running the script below produces the following 
error:

ALERT - canary mismatch on erealloc() - heap overflow 
detected (attacker 'REMOTE_ADDR not set', file 
'/home/matt/wg/wg.static/scripts/test2.php', line 14)

The script grabs a file from my site, but feel free to look 
at it in your browser if you don't trust it.

I have been migrating a bunch of data from MySQL to Mongo, 
and there was something in particular about this record.  I 
have done a mb_detect_encoding() on it and it says "ASCII" - 
a hexdump also confirms this.  I have migrated over 3 
million records and this is the only one that has a problem.

I haven't managed to compile my own version of PHP so I 
can't use --enable-debug - If you can't reproduce this, let 
me know and I'll give it another shot.

Cheers!


Reproduce code:
---------------
<?php
$connection = new Mongo();

$db = $connection->selectDB('webgenius');

$tbColl = $db->selectCollection('Text_Block');

$text = file_get_contents('http://webgenius.co.nz/mongo-bug.txt');

$arr = array(
	'text' => $text,
);

$tbColl->insert($arr);
?>


Expected result:
----------------
The array should be inserted into the mongo database.


Actual result:
--------------
canary mismatch on erealloc() - heap overflow detected 
(attacker 'REMOTE_ADDR not set', file 
'/home/matt/wg/wg.static/scripts/test2.php', line 14)