SocketServer.ForkingMixIn.collect_children() does:

       pid, status = os.waitpid(0, options)

By setting pid = 0, it will wait on any children, even
if the children were not started by the SocketServer. 
This causes sporadic test failures:

 
http://mail.python.org/pipermail/python-dev/2006-August/068216.html

It later assumes that if any child finished, that this
server owned the process, which is not a valid
assumption.  Any part of the code could have spawned
the child.

I will fix the test suite, so this problem shouldn't
occur (well at least reduce the likelihood by reaping
the children before each test).

I'm not certain how this problem should really be fixed
(or if it's even worth fixing).  Two possible solutions
are: 
 * only wait on the children we own
 * ignore returned pids that we don't own