xmpp4r problems?

not entirely rails related, but I just wanted to install xmpp4r on a
brandnew leopard system and somehow it does not work:

macPro:tmp joerg$ ruby -v
ruby 1.8.6 (2008-03-03 patchlevel 114) [universal-darwin9.0]
macPro:tmp joerg$ sudo gem -v
1.2.0
macPro:tmp joerg$ sudo gem install xmpp4r
Successfully installed xmpp4r-0.3.2
1 gem installed
macPro:tmp joerg$ sudo gem list --local

*** LOCAL GEMS ***
.
..
...
xmpp4r (0.3.2)

macPro:tmp joerg$ irb

require 'ubygems'

=> true

require 'xmpp4r'

LoadError: no such file to load -- xmpp4r
  from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:32:in
`gem_original_require'
  from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:32:in
`require'
  from (irb):2

???

Any ideas / suggestions? :-/

Cheers,
-J