Please test to make sure this solves the issue.
Check for tornado before running frontend.html tests.
All tests now pass in OSX 10.6 and Ubuntu 10.4.
In Win7, the tornado failures are gone. There is still one (pre-existing, apparently unrelated) test failure which I will report separately.
@ellisonbg - do you want to test for tornado 2.0, rather than just tornado? The server itself requires it, but I'm not sure if the tests would.
That solves the problem for me. I think you can merge this.