preg_match_all Server Crash

<?php
    //  Instead of duplicating the FAQ content in the ReadMe.txt file,
    //  let's simply extract it from the WordPress plugin repository!
    //
    //  This solutution is derived from a discussion found on www.DevNetwork.net.
    //  See full discussion:  http://www.devnetwork.net/viewtopic.php?f=38&t=102670
    //

    /*
    //  Commented regex to extract contents from <div class="main">contents</div>
    //  where "contents" may contain nested <div>s.
    //  Regex uses PCRE's recursive (?1) sub expression syntax to recurs group 1

    $pattern_long = '{                    # recursive regex to capture contents of "main" DIV
    <div\s+class="main"\s*>               # match the "main" class DIV opening tag
      (                                   # capture "main" DIV contents into $1
        (?:                               # non-cap group for nesting * quantifier
          (?: (?!<div[^>]*>|</div>). )++  # possessively match all non-DIV tag chars
        |                                 # or
          <div[^>]*>(?1)</div>            # recursively match nested <div>xyz</div>
        )*                                # loop however deep as necessary
      )                                   # end group 1 capture
    </div>                                # match the "main" class DIV closing tag
    }six';  // single-line (dot matches all), ignore case and free spacing modes ON
    */

    //  WordPress plugin repository places the content in DIV with a class of
    //  "block-content" but there are actually several DIVs that have the same class.
    //  We only want the first one.

    $url = 'http://wordpress.org/extend/plugins/wpgform/faq/' ;
    $response= wp_remote_get($url) ;

    if (is_wp_error($response))
    {
?>
<div class="updated error"><?php _e('Unable to retrive FAQ content from WordPress plugin repository.', WPGFORM_I18N_DOMAIN);?></div>
<?php
    }
    else
    {
?>
<?php
        $data = &$response['body'] ;
        $pattern_short = '{<div\s+[^>]*?class="block-content"[^>]*>((?:(?:(?!<div[^>]*>|</div>).)++|<div[^>]*>(?1)</div>)*)</div>}si';
        $matchcount = preg_match_all($pattern_short, $data, $matches);
        //$matchcount = 0 ;

        //  Did we find something?
        if ($matchcount > 0)
        {
            //  The content we want will be the first match
            echo($matches[1][0]); // print 1st capture group for match number i
        }
        else
        {
?>
    <div class="updated error"><?php _e('Unable to retrive FAQ content from WordPress plugin repository.', WPGFORM_I18N_DOMAIN);?></div>
<?php
        }
    }

?>