i am getting this error like many others posting here.
I tried to look at the xml.php for errors but i just get a blank screen.
here is the specific error in my httpd-error log:
PHP Fatal error: Class 'DOMDocument' not found in /usr/local/www/apache22/data/phpsysinfo/includes/error/class.Error.inc.php on line 159, referer: http://10.1.1.1/phpsysinfo/index.php?disp=dynamic
Maybe you need to enable/disabled some php5 extensions (php5_xml or php5_dom ?)