Problem with rio-0.3.4

Running this script (named riotest) with rio-0.3.3:

require 'rubygems'
require 'rio'
puts rio('riotest').readlines

correctly says:

ruby riotest

require 'rubygems'
require 'rio'
puts rio('riotest').readlines

But with rio-0.3.4 I get:

ruby riotest

.../gems/1.8/gems/rio-0.3.4/lib/rio/ops/file.rb:62:
  uninitialized constant rio::ops::fileordir::existornot (nameerror)
  from ... /site_ruby/1.8/rubygems/custom_require.rb:21:
  in `require'
  from ... /gems/1.8/gems/rio-0.3.4/lib/rio/file.rb:39
  from ... /site_ruby/1.8/rubygems/custom_require.rb:21:
  in `require'
  from ... /gems/1.8/gems/rio-0.3.4/lib/rio/factory.rb:197:
  in `state2class'
  from ... /gems/1.8/gems/rio-0.3.4/lib/rio/factory.rb:206:
  in `try_state_proc'
  from ... /gems/1.8/gems/rio-0.3.4/lib/rio/state.rb:120:
  in `become'
  from ... /gems/1.8/gems/rio-0.3.4/lib/rio/path.rb:80:
  in `efile'
  from ... /gems/1.8/gems/rio-0.3.4/lib/rio/path.rb:65:
  in `when_missing'
  from ... /gems/1.8/gems/rio-0.3.4/lib/rio/state.rb:134:
  in `method_missing'
  from ... /gems/1.8/gems/rio-0.3.4/lib/rio/state.rb:136:
  in `method_missing'
  from ... /gems/1.8/gems/rio-0.3.4/lib/rio/if/stream.rb:188:
  in `readlines'
  from riotest:3

(I tweaked the output a little for clarity)

Any ideas?

···

--
Wybo