Problem loading modules through ActiveSupport on_load

Working with modules to group certain methods. Currently I have this
set up and it works:

**# app/models/a.rb**

    class A
      has_history
    end

**# lib/history.rb**

    module History
      module Model
        def self.included(base)
          base.send :extend, ClassMethods
        end

        module ClassMethods
          def has_history(options = {})
            send :include, InstanceMethods
          end
        end

        module InstanceMethods
          # methods ...
        end
      end
    end

**# config/application.rb**

    config.autoload_paths += %W(#{config.root}/lib)

**# config/environment.rb**

    ActiveSupport.on_load(:active_record) do
      include History::Model
    end

This works, the methods are mixed into the models.

In a similar way, I wanted to package another set of methods with a
different purpose in the same application and I followed the same
approach:

**# lib/history.rb**

    module Fleet
      module Model
        def self.included(base)
          base.extend ClassMethods
        end

        module ClassMethods
          def has_fleet(options = {})
            send :include, InstanceMethods
          end
        end

        module InstanceMethods
        # methods ...
        end
      end
    end

**# config/environment.rb**

    ActiveSupport.on_load(:active_record) do
      include History::Model
      include Fleet::Model
    end

But, I don't think the module Fleet::Model is loaded and throws up
errors when I do this in a model which is supposed to include this
module:

**# app/models/b.rb**

    class B
      has_fleet
    end

I am unable to get around this and not sure what is going wrong here.
Throws up the following errors:

    syed@rails:~/work/projects/mapunity/pinpoint$ rails c
    /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activerecord-3.0.7/lib/
active_record/base.rb:1009:in `method_missing': undefined local
variable or method `has_fleet' for #<Class:0x9c2f200> (NameError)
      from /home/syed/work/projects/mapunity/pinpoint/app/models/
account.rb:2:in `<class:Account>'
      from /home/syed/work/projects/mapunity/pinpoint/app/models/
account.rb:1:in `<top (required)>'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:454:in `load'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:454:in `block in load_file'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:596:in `new_constants_in'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:453:in `load_file'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:340:in `require_or_load'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:491:in `load_missing_constant'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:183:in `block in const_missing'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:181:in `each'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:181:in `const_missing'
      from /home/syed/work/projects/mapunity/pinpoint/app/admin/
accounts.rb:1:in `<top (required)>'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:235:in `load'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:235:in `block in load'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:225:in `block in load_dependency'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:596:in `new_constants_in'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:225:in `load_dependency'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:235:in `load'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activeadmin-0.3.2/
lib/active_admin/application.rb:132:in `block in load!'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activeadmin-0.3.2/
lib/active_admin/application.rb:132:in `each'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activeadmin-0.3.2/
lib/active_admin/application.rb:132:in `load!'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activeadmin-0.3.2/
lib/active_admin/application.rb:155:in `routes'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activeadmin-0.3.2/
lib/active_admin.rb:63:in `routes'
      from /home/syed/work/projects/mapunity/pinpoint/config/routes.rb:
2:in `block in <top (required)>'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.7/lib/
action_dispatch/routing/route_set.rb:233:in `instance_exec'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.7/lib/
action_dispatch/routing/route_set.rb:233:in `draw'
      from /home/syed/work/projects/mapunity/pinpoint/config/routes.rb:
1:in `<top (required)>'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:235:in `load'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:235:in `block in load'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:225:in `block in load_dependency'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:596:in `new_constants_in'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:225:in `load_dependency'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:235:in `load'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/application.rb:127:in `block in reload_routes!'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/application.rb:127:in `each'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/application.rb:127:in `reload_routes!'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activeadmin-0.3.2/
lib/active_admin/reloader.rb:17:in `block in attach!'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/callbacks.rb:420:in `_run_prepare_callbacks'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.7/lib/
action_dispatch/middleware/callbacks.rb:40:in `initialize'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.7/lib/
action_dispatch/middleware/stack.rb:33:in `new'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.7/lib/
action_dispatch/middleware/stack.rb:33:in `build'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.7/lib/
action_dispatch/middleware/stack.rb:79:in `block in build'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.7/lib/
action_dispatch/middleware/stack.rb:79:in `each'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.7/lib/
action_dispatch/middleware/stack.rb:79:in `inject'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/actionpack-3.0.7/lib/
action_dispatch/middleware/stack.rb:79:in `build'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/application.rb:162:in `app'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/application/finisher.rb:35:in `block in <module:Finisher>'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/initializable.rb:25:in `instance_exec'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/initializable.rb:25:in `run'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/initializable.rb:50:in `block in run_initializers'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/initializable.rb:49:in `each'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/initializable.rb:49:in `run_initializers'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/application.rb:134:in `initialize!'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/application.rb:77:in `method_missing'
      from /home/syed/work/projects/mapunity/pinpoint/config/
environment.rb:5:in `<top (required)>'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:239:in `require'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:239:in `block in require'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:225:in `block in load_dependency'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:596:in `new_constants_in'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:225:in `load_dependency'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.7/
lib/active_support/dependencies.rb:239:in `require'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/application.rb:103:in `require_environment!'
      from /home/syed/.rvm/gems/ruby-1.9.2-p0/gems/railties-3.0.7/lib/
rails/commands.rb:22:in `<top (required)>'
      from script/rails:6:in `require'
      from script/rails:6:in `<main>'