Enhancement Request: generate application using previous Rails version

Does the standard gem wrapper method:

rails _2.3.5_ ...args...

Not work for this case?

After trying the standard gem wrapper, I'm seeing the following issue:

$ rvm ruby-head

$ ruby -v
ruby 1.9.2dev (2010-01-18 trunk 26340) [powerpc-darwin9.8.0]

$ gem list rails

*** LOCAL GEMS ***

rails (3.0.0.beta, 3.0.pre, 2.3.5)

$ gem list rails

*** LOCAL GEMS ***

rails (3.0.0.beta, 2.3.5)

$ rails _2.3.5_ blog235
/opt/local/lib/ruby/gems/1.9.1/gems/rubygems-update-1.3.5/lib/rubygems.rb:827:in `report_activate_error': RubyGem version error: railties(3.0.pre not = 2.3.5) (Gem::LoadError)
    from /opt/local/lib/ruby/gems/1.9.1/gems/rubygems-update-1.3.5/lib/rubygems.rb:261:in `activate'
    from /opt/local/lib/ruby/gems/1.9.1/gems/rubygems-update-1.3.5/lib/rubygems.rb:68:in `gem'
    from /Users/conradwt/.rvm/gems/ruby-head/bin/rails:18:in `<main>'

$ rvm system

$ ruby -v
ruby 1.9.1p376 (2009-12-07 revision 26041) [powerpc-darwin9]

$ gem list rails

*** LOCAL GEMS ***

rails (3.0.0.beta, 2.3.5)

$ rails _2.3.5_ blog235
/opt/local/lib/ruby/gems/1.9.1/gems/rubygems-update-1.3.5/lib/rubygems.rb:827:in `report_activate_error': RubyGem version error: railties(3.0.0.beta not = 2.3.5) (Gem::LoadError)
    from /opt/local/lib/ruby/gems/1.9.1/gems/rubygems-update-1.3.5/lib/rubygems.rb:261:in `activate'
    from /opt/local/lib/ruby/gems/1.9.1/gems/rubygems-update-1.3.5/lib/rubygems.rb:68:in `gem'
    from /opt/local/bin/rails:18:in `<main>'

I'm having a similar issue. I'm not using rvm. Has anyone been able to get this working? If so, how?

$ ruby -v
ruby 1.8.7 (2008-08-11 patchlevel 72) [universal-darwin10.0]
$ gem list rails
rails (3.0.0.beta, 2.3.5, 2.3.4, 2.2.2, 1.2.6)
$ rails 2.3.5 code
/Library/Ruby/Site/1.8/rubygems.rb:777:in report_activate_error': RubyGem version error: railties(3.0.0.beta not = 2.3.5) (Gem::LoadError)
  from /Library/Ruby/Site/1.8/rubygems.rb:211:inactivate'
  from /Library/Ruby/Site/1.8/rubygems.rb:1056:in gem'
  from /usr/bin/rails:18</code>
</pre>

The italic "2.3.5" part actually had underscores around it, btw...