Strange issue with bundler and nokogiri

Gemfile

source "http://rubygems.org"

gem "nanoc"
gem "loofah"
gem "nokogiri"
gem "pygments.rb"

Gemfile.lock

GEM
  remote: http://rubygems.org/
  specs:
    blankslate (2.1.2.4)
    colored (1.2)
    cri (2.3.0)
      colored (>= 1.2)
    ffi (1.0.11)
    loofah (1.2.1)
      nokogiri (>= 1.4.4)
    nanoc (3.4.0)
      cri (~> 2.2)
    nokogiri (1.5.4)
    pygments.rb (0.2.12)
      rubypython (~> 0.5.3)
    rubypython (0.5.3)
      blankslate (>= 2.1.2.3)
      ffi (~> 1.0.7)

PLATFORMS
  ruby

DEPENDENCIES
  loofah
  nanoc
  nokogiri
  pygments.rb

LoadError

[x@y master]$ irb
irb(main):001:0> require "nokogiri"
=> true
irb(main):002:0> exit
[x@y master]$ irb
irb(main):001:0> require "bundler/setup"
=> true
irb(main):002:0> require "nokogiri"
LoadError: cannot load such file -- nokogiri/nokogiri
	from /usr/share/gems/gems/nokogiri-1.5.4/lib/nokogiri.rb:27:in `require'
	from /usr/share/gems/gems/nokogiri-1.5.4/lib/nokogiri.rb:27:in `<top (required)>'
	from (irb):2:in `require'
	from (irb):2
	from /usr/bin/irb:12:in `<main>'
irb(main):003:0> exit
[x@y master]$ irb
irb(main):001:0> require "bundler/setup"
=> true
irb(main):002:0> require "pygments"
LoadError: cannot load such file -- ffi_c
	from /usr/share/gems/gems/ffi-1.0.11/lib/ffi.rb:11:in `require'
	from /usr/share/gems/gems/ffi-1.0.11/lib/ffi.rb:11:in `rescue in <top (required)>'
	from /usr/share/gems/gems/ffi-1.0.11/lib/ffi.rb:2:in `<top (required)>'
	from /usr/share/gems/gems/rubypython-0.5.3/lib/rubypython/python.rb:1:in `require'
	from /usr/share/gems/gems/rubypython-0.5.3/lib/rubypython/python.rb:1:in `<top (required)>'
	from /usr/share/gems/gems/rubypython-0.5.3/lib/rubypython.rb:33:in `require'
	from /usr/share/gems/gems/rubypython-0.5.3/lib/rubypython.rb:33:in `<top (required)>'
	from /usr/share/gems/gems/pygments.rb-0.2.12/lib/pygments/ffi.rb:1:in `require'
	from /usr/share/gems/gems/pygments.rb-0.2.12/lib/pygments/ffi.rb:1:in `<top (required)>'
	from /usr/share/gems/gems/pygments.rb-0.2.12/lib/pygments.rb:2:in `require'
	from /usr/share/gems/gems/pygments.rb-0.2.12/lib/pygments.rb:2:in `<top (required)>'
	from (irb):2:in `require'
	from (irb):2
	from /usr/bin/irb:12:in `<main>'
irb(main):003:0> exit
[x@y master]$ bundle -v
Bundler version 1.1.4
[x@y master]$ gem -v
1.8.24
[x@y master]$ ruby -v
ruby 1.9.3p194 (2012-04-20 revision 35410) [i386-linux]