Rails Gem not found.

I have seen a few posts like this on the internet, with it coming down to the Ruby seems confused about which GEM to use if multiple GEM Directories are installed (typical for OS X 10.5.x). I am trying to learn Rails (yeah I know weird time to learn it with Rails and Merb getting ready to merge), and the rake commands keep complaining that rails 2.3.2 is not present, which it is in the Library Gem Path. How do I tell ruby to use one GEM path instead of another? "environment.rb" is set properly to 2.3.2

>which ruby
/usr/bin/ruby

>which rails
/usr/bin/rails


>mate .profile
export PATH=/usr/local/bin:/Library/Ruby/Gems/1.8:/usr/local/mysql/bin:/opt/local/bin:/opt/local/sbin:$PATH
test -r /sw/bin/init.sh && . /sw/bin/init.sh



>gem environment
RubyGems Environment:
- RUBYGEMS VERSION: 1.3.2
- RUBY VERSION: 1.8.6 (2008-03-03 patchlevel 114) [universal-darwin9.0]
- INSTALLATION DIRECTORY: /Library/Ruby/Gems/1.8
- RUBY EXECUTABLE: /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby
- EXECUTABLE DIRECTORY: /usr/bin
- RUBYGEMS PLATFORMS:
- ruby
- universal-darwin-9
- GEM PATHS:
- /Library/Ruby/Gems/1.8
- /Users/brad/.gem/ruby/1.8
- /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/gems/1.8
- GEM CONFIGURATION:
- :update_sources => true
- :verbose => true
- :benchmark => false
- :backtrace => false
- :bulk_threshold => 1000



Help!!!