RubyGems - Uninitialized Constant Gem::SyckDefaultKey Exception

gistfile1.txt

~/projects/rails_app/ $ ruby script/server
=> Booting Mongrel
=> Rails 2.3.14 application starting on http://0.0.0.0:3000
NOTE: Gem.source_index is deprecated, use Specification. It will be removed on or after 2011-11-01.
Gem.source_index called from /Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/rails/gem_dependency.rb:21.
Exception: NameError: uninitialized constant Gem::SyckDefaultKey
	/Library/Ruby/Gems/1.8/gems/activesupport-2.3.14/lib/active_support/dependencies.rb:466:in `load_missing_constant'
	/Library/Ruby/Gems/1.8/gems/activesupport-2.3.14/lib/active_support/dependencies.rb:106:in `const_missing'
	/Library/Ruby/Site/1.8/rubygems/requirement.rb:180:in `fix_syck_default_key_in_requirements'
	/Library/Ruby/Site/1.8/rubygems/requirement.rb:179:in `each'
	/Library/Ruby/Site/1.8/rubygems/requirement.rb:179:in `fix_syck_default_key_in_requirements'
	/Library/Ruby/Site/1.8/rubygems/requirement.rb:130:in `yaml_initialize'
	/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/yaml.rb:133:in `transfer'
	/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/yaml.rb:133:in `node_import'
	/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/yaml.rb:133:in `load'
	/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/yaml.rb:133:in `load'
	/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/yaml.rb:144:in `load_file'
	/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/yaml.rb:143:in `open'
	/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/1.8/yaml.rb:143:in `load_file'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/rails/vendor_gem_source_index.rb:110:in `load_specification'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/rails/vendor_gem_source_index.rb:48:in `refresh!'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/rails/vendor_gem_source_index.rb:45:in `each'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/rails/vendor_gem_source_index.rb:45:in `refresh!'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/rails/vendor_gem_source_index.rb:29:in `initialize'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/rails/gem_dependency.rb:21:in `new'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/rails/gem_dependency.rb:21:in `add_frozen_gem_path'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/initializer.rb:298:in `add_gem_load_paths'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/initializer.rb:132:in `process'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/initializer.rb:113:in `send'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/initializer.rb:113:in `run'
	/Users/dgollapudi/Documents/Parallels/PC_SHARED/projects/therese_enrollment_notifiers/config/environment.rb:28
	/Library/Ruby/Site/1.8/rubygems/custom_require.rb:55:in `gem_original_require'
	/Library/Ruby/Site/1.8/rubygems/custom_require.rb:55:in `require'
	/Library/Ruby/Gems/1.8/gems/activesupport-2.3.14/lib/active_support/dependencies.rb:182:in `require'
	/Library/Ruby/Gems/1.8/gems/activesupport-2.3.14/lib/active_support/dependencies.rb:547:in `new_constants_in'
	/Library/Ruby/Gems/1.8/gems/activesupport-2.3.14/lib/active_support/dependencies.rb:182:in `require'
	/Library/Ruby/Gems/1.8/gems/rails-2.3.14/lib/commands/server.rb:84
	/Library/Ruby/Site/1.8/rubygems/custom_require.rb:55:in `gem_original_require'
	/Library/Ruby/Site/1.8/rubygems/custom_require.rb:55:in `require'
	script/server:4