not loading authenticated system?

I'm getting a strange error on my mediatemple gridserver, that I'm not
getting on my laptop. It seems like it's not loading
authenticatedsystem? but how I tell for sure? can anyone tell me where
to start looking?

Processing HomepagesController#show (for 72.10.62.145 at 2007-04-26
12:15:44) [GET]
  Session ID: 30a851e90d906c4d07b51943f3e90bd8
  Parameters: {"action"=>"show", "id"=>1, "controller"=>"homepages"}
Rendering layoutfalseactionshowcontent_typetext/html within layouts/
homepages
Rendering homepages/show

ActionView::TemplateError (undefined method `logged_in?' for #<#<Class:
0xb766f2f8>:0xb7616810>) on line #5 of app/views/homepages/show.rhtml:
2: <div id="body">
3: <%= @homepage.body %>
4: </div>
5: <% if logged_in? then %>
6: <%= link_to 'Edit', edit_homepage_path(@homepage) %> |
7: <%= link_to 'Back', homepages_path %>
8: <% end %>
    #{RAILS_ROOT}/app/views/homepages/show.rhtml:5:in
`_run_rhtml_47app47views47homepages47show46rhtml'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_view/base.rb:
326:in `send'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_view/base.rb:
326:in `compile_and_render_template'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_view/base.rb:
301:in `render_template'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_view/base.rb:
260:in `render_file'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
base.rb:806:in `render_file'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
base.rb:738:in `render_with_no_layout'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
base.rb:863:in `render_without_layout'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
base.rb:798:in `render_action_without_active_scaffold'
    #{RAILS_ROOT}/vendor/plugins/active_scaffold/lib/extensions/
action_controller.rb:24:in `render_action'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
base.rb:748:in `render_with_no_layout'
    #{RAILS_ROOT}/vendor/rails/activesupport/lib/active_support/
deprecation.rb:43:in `silence'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
base.rb:747:in `render_with_no_layout'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
layout.rb:244:in `render_without_benchmark'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
benchmarking.rb:50:in `render_without_active_scaffold'
    /usr/lib/ruby/1.8/benchmark.rb:293:in `measure'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
benchmarking.rb:50:in `render_without_active_scaffold'
    #{RAILS_ROOT}/vendor/plugins/active_scaffold/lib/extensions/
action_controller.rb:13:in `render'
    #{RAILS_ROOT}/app/controllers/homepages_controller.rb:25:in `show'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
mime_responds.rb:167:in `call'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
mime_responds.rb:167:in `respond'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
mime_responds.rb:161:in `each'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
mime_responds.rb:161:in `respond'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
mime_responds.rb:105:in `respond_to'
    #{RAILS_ROOT}/app/controllers/homepages_controller.rb:25:in `show'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
base.rb:1095:in `send'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
base.rb:1095:in `perform_action_without_filters'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:632:in `call_filter'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:634:in `call_filter'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:638:in `call_filter'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:438:in `call'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:637:in `call_filter'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:638:in `call_filter'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:438:in `call'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:637:in `call_filter'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:638:in `call_filter'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:449:in `call'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:637:in `call_filter'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:619:in `perform_action_without_benchmark'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
benchmarking.rb:66:in `perform_action_without_rescue'
    /usr/lib/ruby/1.8/benchmark.rb:293:in `measure'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
benchmarking.rb:66:in `perform_action_without_rescue'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
rescue.rb:83:in `perform_action'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
base.rb:430:in `send'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
base.rb:430:in `process_without_filters'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
filters.rb:624:in `process_without_session_management_support'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
session_management.rb:114:in `process'
    #{RAILS_ROOT}/vendor/rails/actionpack/lib/action_controller/
base.rb:330:in `process'
    #{RAILS_ROOT}/vendor/rails/railties/lib/dispatcher.rb:41:in
`dispatch'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel/rails.rb:78:in `process'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel/rails.rb:76:in `synchronize'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel/rails.rb:76:in `process'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel.rb:618:in `process_client'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel.rb:617:in `each'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel.rb:617:in `process_client'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel.rb:736:in `run'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel.rb:736:in `initialize'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel.rb:736:in `new'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel.rb:736:in `run'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel.rb:720:in `initialize'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel.rb:720:in `new'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel.rb:720:in `run'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel/configurator.rb:271:in `run'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel/configurator.rb:270:in `each'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel/configurator.rb:270:in `run'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/bin/
mongrel_rails:127:in `run'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/lib/
mongrel/command.rb:211:in `run'
    /home/17540/data/rubygems/gems/gems/mongrel-1.0.1-i386-linux/bin/
mongrel_rails:243