php解析XML在5.2版本环境报错，5.3版本正常。
if (isset($_POST['xmldata'])) {
$string="<configuration>".$_POST['xmldata']."</configuration>";
$doc=$xml = new DOMDocument();
$xml->loadXML($string);
...
为什么我表单提交过来的XML文件，页面报错呢？
页面提示信息：
Warning: DOMDocument::loadXML() [domdocument.loadxml]: AttValue: " or ' expected in Entity, line: 2 in /usr/local/apache2/htdocs/dbmanage/xmlfile.php on line 126

Warning: DOMDocument::loadXML() [domdocument.loadxml]: attributes construct error in Entity, line: 2 in /usr/local/apache2/htdocs/dbmanage/xmlfile.php on line 126

Warning: DOMDocument::loadXML() [domdocument.loadxml]: Couldn't find end of Start Tag add line 2 in Entity, line: 2 in /usr/local/apache2/htdocs/dbmanage/xmlfile.php on line 126

Warning: DOMDocument::loadXML() [domdocument.loadxml]: AttValue: " or ' expected in Entity, line: 3 in /usr/local/apache2/htdocs/dbmanage/xmlfile.php on line 126

Warning: DOMDocument::loadXML() [domdocument.loadxml]: attributes construct error in Entity, line: 3 in /usr/local/apache2/htdocs/dbmanage/xmlfile.php on line 126

xml格式如下：
  <appSettings>
  <add key="cegg" value="true" />
  <add key="dveda" value="true" />
  <add key="acdfe" value="192.168.1.15:10201" />
  <add key="adsf" value="http://xxxx.net/uidimg_default" />
  <add key="cve" value="http://192.168.1.13/packager2" />
  <add key="feed_ee" value="http://xxxx.com/"/>
  </appSettings>

PHP版本：
#php -v
PHP 5.2.12 (cli) (built: Apr 25 2012 21:12:31)

------解决方案--------------------
var_dump($string); // 加上这句，贴出结果来。
$xml->loadXML($string);


------解决方案--------------------
表单POST上来的？enctype是什么? 还是AJAX提上来的？ Content-Type设置了什么？ 看看HTTP_RAW_POST_DATA？