title: calling single tests works but not running all tests in MiniTest
body: <p>I switched from Test Unit to MiniTest in jruby-1.7.13. I also use mocha/integration. My problem is that running 'rake test' brings up Mocha::ExpectationError: unexpected invocation: MyClass.new. With MyClass.new beeing a class defined in the lib folder and used in the test class. I figured out that running the tests separately workds just fine. It looks like a timing or sequence issue. I tried to circumvent it by using setup/teardown to initiate the MyClass.new before each single test, but this does not help. Do I have to mock/stub the MyClass.new? </p>