If you have models in subdirectories in your Rails app (i.e. app/models/billing/, app/models/observers/, etc), you need to add this line to your environment.rb if you upgrade to Edge Rails:
config.autoload_paths += Dir[RAILS_ROOT + '/app/models/*/']
Via: I.NFECTIO.US
Shanti A. Braford blogs here.
If you really want to know, just read this.



