Message3767

Yes it's a 64-bit machine. I put your test into a .py file and ran it 
with Jython and it didn't report any errors..

The results of the second request:

Jython 2.5b0+ (trunk:5557, Nov 8 2008, 16:33:47) 
[Java HotSpot(TM) 64-Bit Server VM (Sun Microsystems Inc.)] on 
java1.5.0_06
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os._native_posix
True
>>> 

The errors with jython-elementtree went away because they recently 
changed the installation procedure (now using an install.py instead of 
setuptools-based setup.py). I'll see if I can create a better reproducible test for this issue.