Description:
------------
I tried this with php 5.3.8 and 5.3.2 with the same results.

Test script:
---------------
<?php
$content = '<div class="private-sales-index">
<div class="box">
<div class="content">
<h1>Welcome to our Exclusive Online Store</h1>
<p>If you are a registered member, please <a href="{{store url="customer/account/login"}}">log in here</a>.</p>
<p class="description">Magento is the leading hub for exclusive specialty items for all your home, apparel and entertainment needs!</p>
</div>
</div>
</div>';

$content = mbereg_replace("\r\n", ' ', $content);
$content = mbereg_replace("\n", ' ', $content);
var_dump($content);
var_dump(mb_ereg('(.*?\s){100}', $content, $_m));
var_dump($_m);


Expected result:
----------------
$content should be truncated to string that contains ~100 words.

Actual result:
--------------
Script executing hangs.