rake task can't find installed gems

I'm running a rake task and it complains there are "Missing gems" even though they are indeed installed. However from further inspection, it appears it is not looking in my GEM PATH (/usr/local/lib/ruby/1.8) but instead is looking in

/usr/lib/ruby/gems/1.8.

my gem env: RubyGems Environment:   - RUBYGEMS VERSION: 1.3.7   - RUBY VERSION: 1.8.7 (2010-04-19 patchlevel 253) [x86_64-linux]   - INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/1.8   - RUBY EXECUTABLE: /usr/local/bin/ruby   - EXECUTABLE DIRECTORY: /usr/local/bin   - RUBYGEMS PLATFORMS:     - ruby     - x86_64-linux   - GEM PATHS:      - /usr/local/lib/ruby/gems/1.8      - /home/allen/.gem/ruby/1.8   - GEM CONFIGURATION:      - :update_sources => true      - :verbose => true      - :benchmark => false      - :backtrace => false      - :bulk_threshold => 1000      - :sources => ["http://rubygems.org/", "RubyGems.org | your community gem host]   - REMOTE SOURCES:      - http://rubygems.org/      - http://gemcutter.org/