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