問題の原因がわかりません。
Rails3.1.1とActiveAdmin0.4.0を使用しています。WebサーバーはWEBrick1.3.1です。
各リクエスト、ActiveAdminファイルはログに表示されます。例えば：
Started GET "/admin/" for 127.0.0.1 at 2012-04-17 21:28:37 +0200
[nil, ["path/to/the/app/admin", "path/to/the/app/admin/modela.rb", "path/to/the/app/admin/modelb.rb", "path/to/the/app/admin/modelc.rb", "path/to/the/app/admin/modeld.rb", "path/to/the/app/admin/modele.rb", "path/to/the/app/admin/modelf.rb", "path/to/the/app/admin/modelg.rb", "path/to/the/app/admin/modelh.rb", "path/to/the/app/admin/modeli.rb"]]
Processing by Admin::DashboardController#index as HTML
Completed 401 Unauthorized in 7ms
app / admin / dashboards.rb：
ActiveAdmin::Dashboards.build do
end
ページに関係なく、ActiveAdminファイルはログに表示されます...環境（開発、ステージング、本番など）に関係なく
別のページ、別の例：
[...]
Started GET "/assets/jquery-1.7.1.min.js?body=1" for 127.0.0.1 at 2012-04-18 12:37:40 +0200
[nil, ["path/to/the/app/admin", "path/to/the/app/admin/modela.rb", "path/to/the/app/admin/modelb.rb", "path/to/the/app/admin/modelc.rb", "path/to/the/app/admin/modeld.rb", "path/to/the/app/admin/modele.rb", "path/to/the/app/admin/modelf.rb", "path/to/the/app/admin/modelg.rb", "path/to/the/app/admin/modelh.rb", "path/to/the/app/admin/modeli.rb"]]
Served asset /jquery-1.7.1.min.js - 304 Not Modified (0ms)
Started GET "/assets/jquery.ui.datepicker-fr.js?body=1" for 127.0.0.1 at 2012-04-18 12:37:40 +0200
[nil, ["path/to/the/app/admin", "path/to/the/app/admin/modela.rb", "path/to/the/app/admin/modelb.rb", "path/to/the/app/admin/modelc.rb", "path/to/the/app/admin/modeld.rb", "path/to/the/app/admin/modele.rb", "path/to/the/app/admin/modelf.rb", "path/to/the/app/admin/modelg.rb", "path/to/the/app/admin/modelh.rb", "path/to/the/app/admin/modeli.rb"]]
Served asset /jquery.ui.datepicker-fr.js - 304 Not Modified (0ms)
Started GET "/assets/jquery_ujs.js?body=1" for 127.0.0.1 at 2012-04-18 12:37:40 +0200
[nil, ["path/to/the/app/admin", "path/to/the/app/admin/modela.rb", "path/to/the/app/admin/modelb.rb", "path/to/the/app/admin/modelc.rb", "path/to/the/app/admin/modeld.rb", "path/to/the/app/admin/modele.rb", "path/to/the/app/admin/modelf.rb", "path/to/the/app/admin/modelg.rb", "path/to/the/app/admin/modelh.rb", "path/to/the/app/admin/modeli.rb"]]
Served asset /jquery_ujs.js - 304 Not Modified (0ms)
[...]
各リクエストには次のものがあります。
[nil, ["path/to/the/app/admin", "path/to/the/app/admin/modela.rb", "path/to/the/app/admin/modelb.rb", "path/to/the/app/admin/modelc.rb", "path/to/the/app/admin/modeld.rb", "path/to/the/app/admin/modele.rb", "path/to/the/app/admin/modelf.rb", "path/to/the/app/admin/modelg.rb", "path/to/the/app/admin/modelh.rb", "path/to/the/app/admin/modeli.rb"]]
何か案は？