An older version of Cookie.py that I used in Mailman
allowed : (colon) in the keys.  The version that's in
Python right now does not.  The question comes down to
whether Cookie.py should be a strict interpretation of
RFCs 2109 and 2068 (which appears to mandate such keys
be enclosed in quotes) or a looser interpretation.  

On the one hand, it shouldn't allow you to break the
standards, but OTOH most browsers allow this, and
besides, it's entirely possible that you'll get
ill-conformant cookie data.  Be liberal in what you
accept and strict in what you generate.

Here's the thread in python-dev:

http://mail.python.org/pipermail/python-dev/2001-October/017722.html

Mostly I'm submitting this bug so it doesn't get buried
in my inbox.  Posted patch is attached.