config.cache_classes value ignored in development mode under Apache 2

I'm running latest version of RoR under Apache 2 (using a virtual host), if I change the environment config within the virtual host (SetEnv RAILS_ENV development) then it changes environment as expected.

However when I'm working with views and not the model I would like have RoR cache the model files, I have tried changing the value of config.cache_classes to true in the config/environment/development.rb file but that doesn't seem to make any difference.

I've not tried WEBrick or anything else, I just jumped straight into Apache 2 as that is how it will be deployed on the live servers.

Any ideas why this isn't working?