No such File to Load — rest_client (Rails 3)

Wenn ich thin start dies ist die Fehlermeldung die ich bekomme:

$ thin start
>> Using rack adapter
/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:239:in `require': no such file to load -- rest_client (LoadError)
    from /.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:239:in `block in require'
    from /.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:225:in `block in load_dependency'
    from /.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:596:in `new_constants_in'
    from /.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:225:in `load_dependency'
    from /.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.9/lib/active_support/dependencies.rb:239:in `require'
    from /.rvm/gems/ruby-1.9.2-p0/gems/stripe-1.5.13/lib/stripe.rb:9:in `<top (required)>'
    from /.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.7/lib/bundler/runtime.rb:64:in `require'
    from /.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.7/lib/bundler/runtime.rb:64:in `block (2 levels) in require'
    from /.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.7/lib/bundler/runtime.rb:62:in `each'
    from /.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.7/lib/bundler/runtime.rb:62:in `block in require'
    from /.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.7/lib/bundler/runtime.rb:51:in `each'
    from /.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.7/lib/bundler/runtime.rb:51:in `require'
    from /.rvm/gems/ruby-1.9.2-p0/gems/bundler-1.0.7/lib/bundler.rb:112:in `require'
    from /app/config/application.rb:7:in `<top (required)>'
    from <internal:lib/rubygems/custom_require>:29:in `require'
    from <internal:lib/rubygems/custom_require>:29:in `require'
    from /app/config/environment.rb:2:in `<top (required)>'
    from <internal:lib/rubygems/custom_require>:29:in `require'
    from <internal:lib/rubygems/custom_require>:29:in `require'
    from /app/config.ru:3:in `block in <main>'
    from /.rvm/gems/ruby-1.9.2-p0/gems/rack-1.2.3/lib/rack/builder.rb:46:in `instance_eval'
    from /.rvm/gems/ruby-1.9.2-p0/gems/rack-1.2.3/lib/rack/builder.rb:46:in `initialize'
    from /app/config.ru:1:in `new'
    from /app/config.ru:1:in `<main>'
    from /.rvm/gems/ruby-1.9.2-p0/gems/thin-1.2.11/lib/rack/adapter/loader.rb:36:in `eval'
    from /.rvm/gems/ruby-1.9.2-p0/gems/thin-1.2.11/lib/rack/adapter/loader.rb:36:in `load'
    from /.rvm/gems/ruby-1.9.2-p0/gems/thin-1.2.11/lib/rack/adapter/loader.rb:45:in `for'
    from /.rvm/gems/ruby-1.9.2-p0/gems/thin-1.2.11/lib/thin/controllers/controller.rb:169:in `load_adapter'
    from /.rvm/gems/ruby-1.9.2-p0/gems/thin-1.2.11/lib/thin/controllers/controller.rb:73:in `start'
    from /.rvm/gems/ruby-1.9.2-p0/gems/thin-1.2.11/lib/thin/runner.rb:185:in `run_command'
    from /.rvm/gems/ruby-1.9.2-p0/gems/thin-1.2.11/lib/thin/runner.rb:151:in `run!'
    from /.rvm/gems/ruby-1.9.2-p0/gems/thin-1.2.11/bin/thin:6:in `<top (required)>'
    from /.rvm/gems/ruby-1.9.2-p0/bin/thin:19:in `load'
    from /.rvm/gems/ruby-1.9.2-p0/bin/thin:19:in `<main>'

Jemand irgendwelche Gedanken?

Edit: ich habe versucht mit sudo gem install rest-client, und obwohl das gem installiert, ich bin noch immer die Fehlermeldung, wenn ich laufen thin start.