First, you should dump the value of environ['trac.locale'] to check if
it matches what you expect.
i.e. install Trac from source as explained here
(http://trac.edgewall.org/wiki/TracDownload#Tracstable) and modify the
trac/web/main.py before line 396 to add:
print>>sys.stderr, "environ['trac.locale'] == ", environ['trac.locale']
(as you don't have a log handler available there; the debug output
should appear in the same apache log file as you've shown us above).
If it's the value you have configured in httpd.conf, then pick /another/
value, one supported by your version of Python (check on the command
line). If not, then something is wrong with your configuration.
-- Christian