[Zope] plone newbie q / plone install error

[simon litwan]

hi all

it's ok to ask about plone on this list.

i got a brocken product if i tried to install plone.
i allready installed cmf 1.3
i not understand why plon doesn's find Products.CMFCalendar.Extensions,
although i see the folder with with a file called Install.py.


Traceback (most recent call last):
  File
"/home/simon/software/Zope-2.5.1-linux2-x86/Zope-2.5.1-linux2-x86/lib/python
/OFS/Application.py", line 531, in import_product
    File
"/opt/Zope-2.5.1-linux2-x86/lib/python/Products/CMFPlone/__init__.py", line
7, in ?
        import PloneFolder, Portal
         File
"/opt/Zope-2.5.1-linux2-x86/lib/python/Products/CMFPlone/Portal.py", line
11, in ?
             from Products.CMFCalendar.Extensions import Install as
CalendarInstall
             ImportError: No module named Extensions

hope for help
thanx

simon