Debugging rspec in Netbeans

Hi. I can’t seem to get debugging of rspec specs working in Netbeans.
AFAIK, I’m supposed to be able to just do Command+Shift+F5 with the
spec open in the editor but i get this error:

/Users/admin/src/expresso/vendor/plugins/rspec/lib/spec/test/unit/
autorunner.rb:2:in remove_method': methodprocess_args’ not defined
in Test::Unit::AutoRunner (NameError)
from /Users/admin/src/expresso/vendor/plugins/rspec/lib/spec/
test/unit/autorunner.rb:2
from /usr/local/lib/ruby/site_ruby/1.8/rubygems/
custom_require.rb:27:in gem_original_require' from /usr/local/lib/ruby/site_ruby/1.8/rubygems/ custom_require.rb:27:inrequire’
from /usr/local/lib/ruby/gems/1.8/gems/
activesupport-1.4.2.7707/lib/active_support/dependencies.rb:496:in
require' from /usr/local/lib/ruby/gems/1.8/gems/ activesupport-1.4.2.7707/lib/active_support/dependencies.rb:342:innew_constants_in’
from /usr/local/lib/ruby/gems/1.8/gems/
activesupport-1.4.2.7707/lib/active_support/dependencies.rb:496:in
require' from /Users/admin/src/expresso/vendor/plugins/rspec/lib/spec/ test.rb:1 from /usr/local/lib/ruby/site_ruby/1.8/rubygems/ custom_require.rb:27:ingem_original_require’
… 56 levels…
from /usr/local/lib/ruby/gems/1.8/gems/ruby-debug-ide-0.1.8/
lib/ruby-debug.rb:79:in main' from /usr/local/lib/ruby/gems/1.8/gems/ruby-debug-ide-0.1.8/ bin/rdebug-ide:74 from /usr/local/bin/rdebug-ide:16:inload’
from /usr/local/bin/rdebug-ide:16

Any ideas?