空RSS结果

$raw = file_get_contents($rssURL); 
$xml = new SimpleXmlElement($raw);

echo "<b>RSS Items:</b><br /><br />";
foreach($xml->channel->item as $item) {
    echo $item->title."</br >";
}

libxml 版本:2.6.32; libxml2

我也试过这个代码:

# INSTANTIATE CURL.
$curl = curl_init();

# CURL SETTINGS.
curl_setopt($curl, CURLOPT_URL, $rssURL);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 0);
curl_setopt($curl, CURLOPT_VERBOSE, 1);  
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 1);  

# GRAB THE XML FILE.
$xml = curl_exec($curl);

curl_close($curl);

# SET UP XML OBJECT.
$xmlObj = simplexml_load_string($xml);

echo "<b>RSS Items:</b><br /><br />";
foreach($xmlObj->channel->item as $item) {
    echo $item->title."</br >";
}

echo "<br /><b>var_dump:</b><br><br>";
var_dump(libxml_get_errors())

结果是 array(0) { }

为Windows和Linux编写这段代码有什么区别吗(我不这么认为)?