Sorry, i didn't send that because the output is the same:

root@host:python-2.6.5# ./python -m test.regrtest -w -v
'import site' failed; use -v for traceback
Could not import runpy module

root@catastrix:python-2.6.5# ./python -v
# installing zipimport hook
import zipimport # builtin
# installed zipimport hook
'import site' failed; traceback:
ImportError: No module named site
Python 2.6.5 (r265:79063, May 19 2010, 17:31:05) [C] on aix5
Type "help", "copyright", "credits" or "license" for more information.
 >>>

If I run the command ../python -m test.regrtest -w -v from the Lib 
directory, I get the below output:

root@host:Lib# ../python -m test.regrtest -w -v
'import site' failed; use -v for traceback
Traceback (most recent call last):
   File "runpy.py", line 122, in _run_module_as_main
     "__main__", fname, loader, pkg_name)
   File "runpy.py", line 34, in _run_code
     exec code in run_globals
   File "/sw_install/python-2.6.5/Lib/test/regrtest.py", line 124, in 
<module>
     import cStringIO
ImportError: No module named cStringIO

Thanks

Orlando