Problem when Installing Redmine

I'm trying to install Redmine and was followed steps as mentioned on page http://www.redmine.org/projects/redmine/wiki/RedmineInstall, but I get an error in the step-8, the message was:

D:\Permana\Develop\Ruby\redmine-1.1.2>ruby script/server webrick -e production
=> Booting WEBrick
=> Rails 2.3.5 application starting on http://0.0.0.0:3000
D:/Permana/Develop/Ruby/redmine-1.1.2/config/../vendor/rails/railties/lib/rails/gem_dependency.rb:119:in `requirement': undefined local variable or method `version_requirements' for #<Rails::GemDependency:0x33ca6f8> (NameError)
        from C:/Ruby187/lib/ruby/site_ruby/1.8/rubygems.rb:254:in `activate'
        from C:/Ruby187/lib/ruby/site_ruby/1.8/rubygems.rb:1204:in `gem'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/config/../vendor/rails/railties/lib/rails/gem_dependency.rb:73:in `add_load_paths'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/config/../vendor/rails/railties/lib/initializer.rb:301:in `add_gem_load_paths'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/config/../vendor/rails/railties/lib/initializer.rb:301:in `each'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/config/../vendor/rails/railties/lib/initializer.rb:301:in `add_gem_load_paths'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/config/../vendor/rails/railties/lib/initializer.rb:132:in `process'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/config/../vendor/rails/railties/lib/initializer.rb:113:in `send'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/config/../vendor/rails/railties/lib/initializer.rb:113:in `run'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/config/environment.rb:20
        from C:/Ruby187/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:29:in`gem_original_require'
        from C:/Ruby187/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:29:in`require'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/vendor/rails/activesupport/lib/active_support/dependencies.rb:开发者_开发问答156:in `require'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/vendor/rails/activesupport/lib/active_support/dependencies.rb:521:in `new_constants_in'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/vendor/rails/activesupport/lib/active_support/dependencies.rb:156:in `require'
        from D:/Permana/Develop/Ruby/redmine-1.1.2/vendor/rails/railties/lib/commands/server.rb:84
        from C:/Ruby187/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:29:in`gem_original_require'
        from C:/Ruby187/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:29:in`require'
        from script/server:3

D:\Permana\Develop\Ruby\redmine-1.1.2>

I try to open http://localhost:3000/ and returns 404.

I know nothing about Ruby on Rails but I'm good at PHP. I really interested in Redmine after trying the demo and plan to Integrate it with SVN

This problem is almost definitely your version of Ruby Gems. Redmine has problems with version 1.5+ of gems.

The output of gem -v on your system will confirm it - if it's >= 1.5.0 you'd be best installing an older version instead (until they release Redmine 1.2, according to that bug report).