I have two systems running the same set of Django unittests. Some of the tests use the @unittest.expectedFailure decorator. 
On one system, these are running fine and reporting at the end of the test run OK (expected failures=10, unexpected successes=2). 
On the other system, the same tests error, but raise _ExpectedFailure and _UnexpectedSuccess without tracebacks.
Has anyone seen this behavior before? Is it a configuration issue? Both systems are running Python 2.7, Django 1.3, and have unittest and unittest2 installed.
I have the problem and I got it to work by deleting the /usr/local/lib/python2.7 and then reinstalling everything from scratch.
The reason for this I believe is that python may not have cleared it's python object and cache files(*.pyc, *.pyo) from it's working directory. That is, not YOUR project's directory but where python actually runs from.
Not sure if that's it but it worked for me!!
Python raising _ExpectedFailure for unittests with @unittest.expectedFailure