RubyCocoa an RubyGems broken after last Ruby update

Hey all, after last ruby update (to 1.8.5) i get RubyGems broken. even a simple gem command as : ~%> gem list -l fails to : /opt/local/lib/ruby/site_ruby/1.8/rubygems/cmd_manager.rb:52:in `initialize': uninitialized constant Gem::CommandManager::HelpCommand (NameError) from /opt/local/lib/ruby/site_ruby/1.8/rubygems/cmd_manager.rb:46:in `new' from /opt/local/lib/ruby/site_ruby/1.8/rubygems/cmd_manager.rb:46:in `instance' from /opt/local/lib/ruby/site_ruby/1.8/rubygems/gem_runner.rb:25:in `run' from /opt/local/bin/gem:23 someone knows a workaround. is rubygems available from macport ? best, Yvon