How can I get autocomplete to work for IntelliJ Ruby plugin?

I am using IntelliJ IDEA 9.0.4 with the latest ve开发者_C百科rsion of the Ruby plugin and JRuby 1.6.0. Autocomplete doesn't seem to work. Pressing ctrl-space only shows me a few top level things.

require 'rubygems'
require 'mechanize'
agent = Mechanize.new

If I type M and ctrl-space I would expect to see Mechanize in the list but I get nothing. If I ctrl-space on an empty line I get a few top level things (FILE, LINE, alias, begin...).