Try putting your file into vendor/plugins/your_plugin/lib/my_plugin/my_class.rb instead of your_plugin/lib/my_class.rb when its MyPlugin::MyClass. When there's a module involved, Rails' autoloading assumes a directory.
Ah thank you that was indeed the problem. And it was working on edge, and not 1.1.6 because the new Dependency code does not have this limitation.
Thanks for the help!