domxml_open_file doesn't open DOMXML file

Hello, I am currently trying my hand at a Horde installation, which heavyly depends on PHP, and PEAR. The environment: - Operating system: SunOS 5.9 Generic_118558-38 sun4u sparc SUNW,Sun-Fire-V240 - The HTTPD server: Apache/1.3.37 (Unix) mod_ssl/2.8.28 OpenSSL/0.9.7i PHP/4.4.4 - PEAR Version: 1.5.0 - PHP Version: 4.4.4 - Zend Engine Version: 1.3.0 See also: <https://webmailtest.rz.uni-konstanz.de/phpinfo.php>. Since my colleague has installed PHP 4.4.4, the domxml_open_file() function is broken: it aborts the calling PHP program, so that no HTML output is sent to the browser. I have written a small PHP programm to try domxml_open_file on an XML source file, cf. attached test-domxml.php. As there is no output, whatsoever, once domxml_open_file is called, I have inserted a submit button to effect domxml_open_file's invocation and display of its results. Above this button, test-domxml.php reveals some details about our PHP installation, and then demonstrates that a readable XML source file is selected for the test. Also attached are three test results: test-domxml-webmailtest.htm: the HTML output from test-domxml.php on the faulty PHP installation before the "Test now" button is hit, showing installation details and demonstrating that the selected XML file is indeed readable; test-domxml-webmailtest.http: the HTTP traffic caused by hitting that button, demonstrating that "HTTP/1.x 200 OK" is the whole response from the faulty server; test-domxml-webmail.htm: output from a copy of test-domxml.php, as run on a server running still PHP 4.4.2, after the "test now" button was hit, demonstrating that domxml_open_file() has delivered its results. Now the big question is: - What could be the reason for that erratic behaviour? - How can I efficiently locate the source of that error? - What could I do to mend our PHP installation? Thank you for any hint. A link to some "Troubleshooting PHP installations" docu would serve as a starting-point. (I have seen docu devoted to the question of troubleshooting in PHP applications; however, that does not help in any way, as I know already the ppertinent location in my PHP program.) Note that I know next to nothing about compiling, and packaging, PHP: This has be done by colleagues. Of course, they tell me that they have followed the pertinent installation documentation, to a T. So I need some ideas what could have been overlooked or misunderstood, I could tell my colleagues to consider. Best wishes, Otto Stolz