[Zope] Upgrade from 2.1.4 to 2.6.1

Hi, I have inherited an old Zope installation as follows: Zope-2.1.4 python1.5 FreeBSD 3.5-STABLE I am attempting to move this site to the following: Zope-2.6.1-linux2-x86 Python-2.1.3 Linux 2.4.18-14 I have Zope up and running in the new environment. I exported all of the folders from the old system and imported them to the new system, however, I can't open any of the folders and the code fails on the site. Does anyone know of any detailed intructions that are usefull in upgrading from such an old release of Zope? Any help tht can be provided is greatly appreciated. Thanks! Brett