If possible can the libxml and libxslt libs get updated to newer versions? Libs can be found here: http://ctindustries.net/dom/libxml/
These version will fix some bugs, provide better libxml/libxslt support, enable namespace support in xml ext and allow for building of xmlwriter in pecl. I have been testing these libs for a bit now (4.3 and 5) and haven't run into any issues. If the libs are update the new php_libxml2.def file needs to be commited. Rob