[Zope] Dechiphering ZServer error report

After running a couple of Zope sites during development for about a month (Zope 2.1.4 installed from source, ZServer on port 8080, ZMySQLDA, PythonMethods, RedHat 6.1), we've seen the server report the following error while running in debug mode (-D) a couple of times: ERROR(200) ZServer uncaptured python exception, closing channel <zhttp_server listening :8080 at 81f5b90> (exceptions.TypeError:unpack non-sequence [usr/local/zope/2-1-4s/ZServer/medusa/asyncore.py|handle_read_event|285] [/usr/local/zope/2-1-4s/ZServer/medusa/asyncore.py|poll|59] [/usr/local/zope/2-1-4s/ZServer/medusa/http_server.py|handle_accept|609]) Is there someone who is familiar with the innards of ZServer who can give me some idea of what is causing these? Thanks.