Im using spork 0.9.2 and rspec 3.0.0. When trying to run test rspec --drb I have an exception
rspec --drb
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems
I started using Spring instead of Spork and that solved it.
It seems to be the new Rails way: http://edgeguides.rubyonrails.org/4_1_release_notes.html#spring-application-preloader