Migration from zope 2.6.1 to 2.7.2

[Massimo Masson]

Hello everybody,
I'm trying to migrate from a working installation of zope 2.6.1 and 
plone 1.0.5 to plone 2 (and zope 2.7.2).

I'm working on a FreeBSD 4.8 release box.

I've updated ports, and portupgrade(d) plone. No compilation errors. I 
stopped zope before portupgrading.

Now i have both zope-2.6.1_1 and zope-2.7, both zope-cmf-1.3.2 and 
zope-cmf-1.4.5, and plone 2.0.3.

My first problem is that now i can't start zope anymore.
I have the executable /usr/local/etc/rc.d/zope.sh, i made a new 
zopeinstance with mkzopeinstance but i still cannot start.

Any suggestion for me?

Thanks in advance,
Max.