Failing rio#mkdir in rio-0.3.4

Ruby
1

This seems quite basic to me, and it worked with rio-0.3.3:

require ‘rubygems’
require ‘rio’
rio(“test”).mkdir

But with rio-0.3.4 it says:

/usr/local/lib/ruby/gems/1.8/gems/rio-0.3.4/lib/rio/ops/dir.rb:77:
uninitialized constant RIO::Ops::FileOrDir::ExistOrNot (NameError)

my ruby is:
ruby 1.8.4 (2005-12-24) [i686-linux]

2

Is there anybody on this list with:

ruby 1.8.3 or 1.8.4 and
rio-0.3.4

who can run this:

require ‘rubygems’
require ‘rio’
p rio(??).mkdir.path

without getting an error message?