Rails install 3.0.1 on Mac OSX 10.5.8

I have successfully installed Git and RVM per the instructions at: http://railstutorial.org/book#sec:install_rails I have followed the install rails instructions to the letter. This is what get:

Rose-MBP:~ roseemmons$ rails -v
/Users/roseemmons/.rvm/gems/ruby-1.9.2-p0@global/specifications/rake-0.8.7.gemspec:27:in `load_specification': uninitialized constant Gem::VERSION (NameError)
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/specification.rb:540:in `initialize'
    from /Users/roseemmons/.rvm/gems/ruby-1.9.2-p0@global/specifications/rake-0.8.7.gemspec:3:in `new'
    from /Users/roseemmons/.rvm/gems/ruby-1.9.2-p0@global/specifications/rake-0.8.7.gemspec:3:in `load_specification'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/source_index.rb:86:in `load_specification'
    from /System/Library/Frameworks/Ru开发者_如何学Goby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/source_index.rb:122:in `load_gems_in'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/source_index.rb:121:in `each'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/source_index.rb:121:in `load_gems_in'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/source_index.rb:75:in `from_gems_in'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems/source_index.rb:47:in `from_installed_gems'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:141:in `source_index'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:310:in `activate'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:65:in `active_gem_with_options'
    from /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/rubygems.rb:50:in `gem'
    from /usr/bin/rails:18

Ugly isn't it? I am learning RoR on my own, so I have no clue what this means or how to fix it. All help is appreciated! Thank you in advance!

rvm --default use 1.9.2

will set the default ruby so that you do not have to enter it every time you launch a terminal

$ rvm use 1.9.2

Apparently RVM doesn't remember this setting so you must enter it every time you launch Terminal.