Sortenie na Member obcas (vacsinou) nefunguje, robilo nam to 500 error

app/models/member.rb:50:in `<=>'
    /home/chili/.rvm/gems/ree-1.8.7-2012.02/bundler/gems/chiliproject_members_view-06dfcdd38abe/app/helpers/members_view_helper.rb:10:in `sort'
    /home/chili/.rvm/gems/ree-1.8.7-2012.02/bundler/gems/chiliproject_members_view-06dfcdd38abe/app/helpers/members_view_helper.rb:10:in `load_members'
    /home/chili/.rvm/gems/ree-1.8.7-2012.02/bundler/gems/chiliproject_members_view-06dfcdd38abe/app/views/projects/settings/_members.rhtml:3:in `_run_rhtml_47home47chili4746rvm47gems47ree451468467452012460247bundler47gems47chiliproject_members_view4506dfcdd38abe47app47views47projects47settings47_members46rhtml_locals_members_object_tab'
    app/views/common/_tabs.rhtml:24:in `_run_rhtml_app47views47common47_tabs46rhtml_locals_object_tabs'
    app/views/common/_tabs.rhtml:23:in `each'
    app/views/common/_tabs.rhtml:23:in `_run_rhtml_app47views47common47_tabs46rhtml_locals_object_tabs'
    app/helpers/application_helper.rb:219:in `render_tabs'
    app/views/projects/settings.rhtml:3:in `_run_rhtml_app47views47projects47settings46rhtml'
    thin (1.4.1) lib/thin/connection.rb:80:in `pre_process'
    thin (1.4.1) lib/thin/connection.rb:78:in `catch'
    thin (1.4.1) lib/thin/connection.rb:78:in `pre_process'
    thin (1.4.1) lib/thin/connection.rb:53:in `process'
    thin (1.4.1) lib/thin/connection.rb:38:in `receive_data'
    eventmachine (0.12.10) lib/eventmachine.rb:256:in `run_machine'
    eventmachine (0.12.10) lib/eventmachine.rb:256:in `run'
    thin (1.4.1) lib/thin/backends/base.rb:63:in `start'
    thin (1.4.1) lib/thin/server.rb:159:in `start'
    thin (1.4.1) lib/thin/controllers/controller.rb:86:in `start'
    thin (1.4.1) lib/thin/runner.rb:185:in `send'
    thin (1.4.1) lib/thin/runner.rb:185:in `run_command'
    thin (1.4.1) lib/thin/runner.rb:151:in `run!'
    thin (1.4.1) bin/thin:6
    /home/chili/.rvm/gems/ree-1.8.7-2012.02/bin/thin:19:in `load'
    /home/chili/.rvm/gems/ree-1.8.7-2012.02/bin/thin:19
    /home/chili/.rvm/gems/ree-1.8.7-2012.02/bin/ruby_noexec_wrapper:14