Missing method (write_manifest) exception when creating a new gem.

[csexton]

I have tried updating the gem, updating all my gems, and updating the
gem system -- but no luck. I even went as far as to uninstall and
reinstall.

I get the following output, any ideas?

$ newgem wizzo -T rspec
create
create doc
create lib
create script
create tasks
create lib/twitter_archive
create History.txt
create Rakefile
create README.rdoc
create PostInstall.txt
create lib/twitter_archive.rb
dependency install_rspec
create spec
exists tasks
create spec/twitter_archive_spec.rb
create spec/spec.opts
create spec/spec_helper.rb
create tasks/rspec.rake
dependency install_rubigen_scripts
exists script
create script/generate
create script/destroy
create script/console
undefined method `write_manifest' for #<RubiGen::Commands::Create:
0x11e1cd8>
/usr/local/lib/ruby/1.8/delegate.rb:268:in `method_missing'
/usr/local/lib/ruby/gems/1.8/gems/rubigen-1.5.0/lib/rubigen/
manifest.rb:46:in `send'
/usr/local/lib/ruby/gems/1.8/gems/rubigen-1.5.0/lib/rubigen/
manifest.rb:46:in `send_actions'
/usr/local/lib/ruby/gems/1.8/gems/rubigen-1.5.0/lib/rubigen/
manifest.rb:45:in `each'
/usr/local/lib/ruby/gems/1.8/gems/rubigen-1.5.0/lib/rubigen/
manifest.rb:45:in `send_actions'
/usr/local/lib/ruby/gems/1.8/gems/rubigen-1.5.0/lib/rubigen/
manifest.rb:30:in `replay'
/usr/local/lib/ruby/gems/1.8/gems/rubigen-1.5.0/lib/rubigen/
commands.rb:41:in `invoke!'
/usr/local/lib/ruby/gems/1.8/gems/rubigen-1.5.0/lib/rubigen/
scripts/../scripts.rb:32:in `run'
/usr/local/lib/ruby/gems/1.8/gems/newgem-1.2.2/bin/newgem:28
/usr/local/bin/newgem:19:in `load'
/usr/local/bin/newgem:19

In case it matters:

$ ruby -v
ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-darwin9.2.1]
$ newgem --version
/usr/local/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake/
gempackagetask.rb:13:Warning: Gem::manage_gems is deprecated and will
be removed on or after March 2009.
newgem 1.2.2