[MacRuby-devel] Issue with running unit tests when requiring rubygems

I wanted to try using mocha to write unit tests with mocks. After requiring "rubygems" a NoMethodError exception was thrown when attempting to run the tests. The method which wasn't found was 'run'. If I remove the call to require "rubygems" my test fails because I can't use mocha but the NoMethodError exception which was thrown is not thrown anymore. Am I missing something? Thanks, Gabriel Ayuso