Installing and upgrading help

installing moodle for the first time and following the Installation Documentation: During the install.php process I continue past the point of entering the database information (The database had been added via the command line instructions in the documentation). I recieve the following error:

Checking your environment ...

We are checking if the various components of your system meet the system requirements

Fatal error: Call to undefined function: xml_parser_create() in /home/www/mirror/subDomains/classes/lib/xmlize.php on line 50

I've confirmed that I have compiled into PHP xml & xmlrpc. Plus I have read the Bug #1927. The Bug didn't provide me a solution that I understood.

My system:
gentoo distribution kernel 2.6.12
apache2.0.58
mysql 4.1.20
php 4.4.2 with the following items compiled into PHP: apache2 berkdb cli crypt gdbm ipv6 mysql ncurses nls pcre readline session spell ssl truetype unicode xml xmlrpc zlib.

Any help is appreciated