[Zope] ZEO or INSTANCE_HOME Problem

[Ben Ocean]

Hi;
I'm building a new Zope server with ZEO and INSTANCE_HOME and I've run into 
this problem when trying to start it:

#./zctl.py start -v
Stopping ZEO pid: 4604 4605
sh: kill: (4604) - No such pid
sh: kill: (4605) - No such pid
Starting ZEO server on 5800
"/usr/local/bin/python" 
/home/httpd/ZopeInstallation/Zope_software_home/lib/python/ZEO/start.py -p 
5800   &
waiting for ZEO server to start 1/200
'import site' failed; use -v for traceback
Traceback (most recent call last):
   File 
"/home/httpd/ZopeInstallation/Zope_software_home/lib/python/ZEO/start.py", 
line 91, in ?
     import sys, os, getopt, string
ImportError: No module named os

No module named os?? Huh? What have I screwed up?
TIA,
BenO