For what it's worth, I added a few debugging statements to a local trunk checkout, and it looks like the port is getting lost somewhere along the way to setup the proxy... So the refused error is accurate and because it's trying the default port 80.  Note also that I think all the Proxy tests fail, even those saying they're ok, because the refused error shows up as a URLError which is what the test expects, but for other reasons.

Oh, and small item I noted while doing the test - the urllib2_localnet module doesn't clean up properly during the tests - all the local servers are left listening on their ports until all the tests are done.  Adding a call to self.httpd.server_close() at the end of run() in LoopbackHttpServerThread appears to fix that.

Here's a sample of one test... 

test_proxy_qop_auth_int_works_or_throws_urlerror (test.test_urllib2_localnet.ProxyAuthTests) ... Init done
Serving HTTP on localhost port 55161
Thread running
Calling handle request
proxy_url: http://localhost:55161
proxy_open: http None None localhost:55161
httplib _set_hostport(localhost,None)
httplib _set_hostport done host=localhost port=80
httplib.connect: Connecting to ('localhost', 80)
back from handle request