Seems to work fine for me when I load a file or a variable containing all of the XML...
<?php
// Get the RSS feed and load it into a SimpleXML object
$file = file_get_contents('rss.xml');
$xml = simplexml_load_string($file) or die('Error loading file');
echo "ID: $xml->id, Name: $xml->name<br/>";
$string = <<<EOF
<?xml version="1.0" encoding="utf-8"?>
<user>
<id>14115042</id>
<name>Vinny Razente</name>
<screen_name>razente</screen_name>
<location>Londrina, PR</location>
<description></description>
<profile_image_url>
http://a1.twimg.com/profile_images/441576330/carinha2_normal.JPG</profile_image_url>
<url>
http://www.orkut.com.br/Main#Profile?rl=mp&uid=510474947387019065</url>
<protected>false</protected>
<followers_count>93</followers_count>
<profile_background_color>ffffff</profile_background_color>
<profile_text_color>919191</profile_text_color>
<profile_link_color>05ad0b</profile_link_color>
<profile_sidebar_fill_color>000000</profile_sidebar_fill_color>
<profile_sidebar_border_color>
000000</profile_sidebar_border_color>
<friends_count>40</friends_count>
<created_at>Mon Mar 10 16:19:52 +0000 2008</created_at>
<favourites_count>0</favourites_count>
<utc_offset>-10800</utc_offset>
<time_zone>Brasilia</time_zone>
<profile_background_image_url>
http://a3.twimg.com/profile_background_images/41540195/Driving_Music_Wallpaper1.jpg</profile_background_image_url>
<profile_background_tile>true</profile_background_tile>
<statuses_count>1368</statuses_count>
<notifications>false</notifications>
<geo_enabled>false</geo_enabled>
<verified>false</verified>
<following>false</following>
<status>
<created_at>Wed Oct 21 23:43:24 +0000 2009</created_at>
<id>5055690064</id>
<text>MORE #DRINK PLEASE!</text>
<source><a href="http://www.tweetdeck.com/"
rel="nofollow">TweetDeck</a></source>
<truncated>false</truncated>
<in_reply_to_status_id></in_reply_to_status_id>
<in_reply_to_user_id></in_reply_to_user_id>
<favorited>false</favorited>
<in_reply_to_screen_name></in_reply_to_screen_name>
<geo />
</status>
</user>
EOF;
$xml = simplexml_load_string($string) or die('Error loading file');
echo "Screen Name: $xml->screen_name, Location: $xml->location";
?>
