Can't get plone to run

[Len Conrad]

Following the instructions from "Professional Plone 4 Development" book.

(not plone/zope from ports)

freebsd 9.0

got pretty far, then:

plone# bin/instance fg

2012-07-09 16:49:55 INFO ZServer HTTP server started at Mon Jul  9 16:49:55 2012
        Hostname: 0.0.0.0
        Port: 8080
2012-07-09 16:49:55 INFO Zope Set effective user to "myname"
Traceback (most recent call last):
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/Zope2/Startup/run.py", line 76, in <module>
    run()
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/Zope2/Startup/run.py", line 22, in run
    starter.prepare()
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/Zope2/Startup/__init__.py", line 86, in prepare
    self.startZope()
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/Zope2/Startup/__init__.py", line 259, in startZope
    Zope2.startup()
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/Zope2/__init__.py", line 46, in startup
    from Zope2.App.startup import startup as _startup
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/Zope2/App/startup.py", line 38, in <module>
    import OFS.Application
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/OFS/Application.py", line 22, in <module>
    import App.Product
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/App/Product.py", line 44, in <module>
    from OFS.Folder import Folder
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/OFS/Folder.py", line 24, in <module>
    from webdav.Collection import Collection
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/webdav/Collection.py", line 30, in <module>
    from webdav.Resource import Resource
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/webdav/Resource.py", line 35, in <module>
    from OFS.event import ObjectClonedEvent
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/OFS/event.py", line 20, in <module>
    import OFS.interfaces
  File "/usr/home/myname/eggs/Zope2-2.13.15-py2.7.egg/OFS/interfaces.py", line 19, in <module>
    from zope.location.interfaces import IPossibleSite
ImportError: cannot import name IPossibleSite

ideas?

Thanks
Len