Rails Server needs restart every time I make changes? why?

Every time I change anything in controller's or in models, I have to restart the server for it to take effect.But that wasn't always the case, it used to work normally before, when I changed anything, but i don't know what happened now ? My Rails version is 3.2.11 In my development environment file i have set config.cache_classes = false. Please help.. My development.rb file is as follows ``` Testapp::Application.configure do # Settings specified here will take precedence over those in config/application.rb # In the development environment your application's code is reloaded on # every request. This slows down response time but is perfect for development # since you don't have to restart the web server when you make code changes. config.cache_classes = false # Log error messages when you accidentally call methods on nil. config.whiny_nils = true # Show full error reports and disable caching config.consider_all_requests_local = true config.action_controller.perform_caching = false # Don't care if the mailer can't send config.action_mailer.raise_delivery_errors = false # Print deprecation notices to the Rails logger config.active_support.deprecation = :log # Only use best-standards-support built into browsers config.action_dispatch.best_standards_support = :builtin # Raise exception on mass assignment protection for Active Record models config.active_record.mass_assignment_sanitizer = :strict # Log the query plan for queries taking more than this (works # with SQLite, MySQL, and PostgreSQL) config.active_record.auto_explain_threshold_in_seconds = 0.5 # Do not compress assets config.assets.compress = false # Expands the lines which load the assets config.assets.debug = true config.action_mailer.default_url_options = { :host => 'localhost:3000' } end ```