为什么我不能在Python 2.4 virtualenv中导入这个Zope组件？

I'm trying to install Plone 3.3rc4 with plone.app.blob and repoze but nothing I've tried has worked so far. For one attempt I've pip-installed repoze.zope2, Plone, and plone.app.blob into a virtualenv. I have I'm trying to install Plone 3.3rc4 with plone.a