Missing Gtk2::HButtonBox and others

[Lynn Wilkins <law acm org>]

I've installed the latest Gtk2.
and checked it.
   cpan> install Gtk2
   CPAN: Storable loaded ok
   Going to read /root/.cpan/Metadata
     Database was generated on Mon, 03 Oct 2005 23:11:35 GMT
   Gtk2 is up to date.

   cpan>
But using command line perl..
   [law lisa project1]$ perl -e "use Gtk2::HButtonBox;"
   Can't locate Gtk2/HButtonBox.pm in @INC (@INC contains: 
/usr/lib/perl5/site_perl/5.8.6/i386-linux-thread-multi           
/usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi 
/usr/lib/perl5/site_perl/5.8.4/i386-linux-thread-multi  .....)

doing a 'find /usr/lib/perl5 -name HButtonBox.pm ' returns nothing. 
(however I do have a HButtonBox.pod
and 'perldoc Gtk2::HButtonBox' shows the pod description of the module. )

How do I correctly install Gtk2-Perl so I have all the modules listed 
here http://gtk2-perl.sourceforge.net/doc/pod/  ?

Thank you.
-law