title: Ruby on Rails: switching from rails 2.3.8 to 3.0.3
body: <p>In my env I require 3.0.3</p>
  
  <p>but when I script/server</p>
  
  <p>I get this: <code>can't activate rails (= 2.3.8, runtime) for [], already activated rails-3.0.3</code></p>
  
  <p>I don't want it to activate 2.3.8.. =\</p>