Problems installing libxml

Hi, everyone,

I'm having trouble installing libxml-ruby and was hoping someone here could
help. I've run into the same problem on both Mac OS X Tiger and Ubuntu Linux
Dapper Drake (6.06 LTS). I've most recently tried installing on Dapper
where I installed Ruby 1.8.5 from source. I've tried both installing the
gem for the latest stable release (0.3.8.4) and also using the tarball for
0.4.0pre01 (although the gem the Rakefile creates is called
libxml-ruby-0.3.9.1.gem). Neither works.

Here's what I get when I try to install the development release:

Building native extensions. This could take a while...
Successfully installed libxml-ruby, version 0.3.9.1
Installing ri documentation for libxml-ruby-0.3.9.1...

Enclosing class/module 'cXMLSaxParser' for module Callbacks not known

No definition for ruby_xml_html_parser_new_file

No definition for ruby_xml_html_parser_new_io

No definition for ruby_xml_html_parser_filename_get

No definition for ruby_xml_html_parser_filename_set

No definition for ruby_xml_html_parser_io_get

No definition for ruby_xml_html_parser_io_set

Enclosing class/module 'mXML' for class Reader not known

Enclosing class/module 'mXML' for class Attribute not known

No definition for input_callbacks_register_input_callbacks

No definition for input_callbacks_add_scheme

No definition for input_callbacks_remove_scheme
Installing RDoc documentation for libxml-ruby-0.3.9.1...

Enclosing class/module 'cXMLSaxParser' for module Callbacks not known

No definition for ruby_xml_html_parser_new_file

No definition for ruby_xml_html_parser_new_io

No definition for ruby_xml_html_parser_filename_get

No definition for ruby_xml_html_parser_filename_set

No definition for ruby_xml_html_parser_io_get

No definition for ruby_xml_html_parser_io_set

Enclosing class/module 'mXML' for class Reader not known

Enclosing class/module 'mXML' for class Attribute not known

No definition for input_callbacks_register_input_callbacks

No definition for input_callbacks_add_scheme

No definition for input_callbacks_remove_scheme

Any suggestions?

Thanks!