Maciej Wisniowski recently responded something to the effect of that I should take a look at my PYTHONPATH and gave me the address for subscribing to Plone. Thank you. I subscribed and posted to Plone, but after a day have received no response :( I looked at my PYTHONPATH, as per your suggestion, but it seemed to be in order. Furthermore, if it were not correct, how could I pull up Zope in any case? I can launch Zope, I just have a problem with the below-mentioned product installation (and maybe others after it). I'm not sure but seems that you have some mess in your directories (or this is because of hardcoded paths in your .pyc files).
Take a look at pathes in your traceback: /usr/local/www/zope/278/lib/python /usr/local/zope/278/lib/python /usr/local/zope/instance1/Products Why there are two different(!) lib/python/ folders? -- Maciej Wisniowski