Pretty much useless information - warning - this might mess things up.
gem environment
RubyGems Environment:
- VERSION: 0.9.4 (0.9.4)
- INSTALLATION DIRECTORY: /Library/Ruby/Gems/1.8
- GEM PATH:
- /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8
- /Library/Ruby/Gems/1.8
- REMOTE SOURCES:
- http://gems.rubyforge.org
cd /Library/Ruby/Gems/1.8
rm cache/*
rm sourcecache
rm gems/act*
rm gems/rails*
rm specifications/act*
rm specifications/rails*