Esto muestran tus logs:
[Mon Nov 21 19:36:27 2011] [error] [client XXX.XXX.XXX.XXX] mod_wsgi (pid=30516): Exception occurred processing WSGI script '/home/malalech/public_html/django.wsgi'., referer: http://malaleche.quijost.com/
[Mon Nov 21 19:36:27 2011] [error] [client XXX.XXX.XXX.XXX] Traceback (most recent call last):, referer: http://malaleche.quijost.com/
[Mon Nov 21 19:36:27 2011] [error] [client XXX.XXX.XXX.XXX] File "/usr/local/lib/python2.7/site-packages/Django-1.3.1-py2.7.egg/django/core/handlers/wsgi.py", line 250, in __call__, referer: http://malaleche.quijost.com/
[Mon Nov 21 19:36:27 2011] [error] [client XXX.XXX.XXX.XXX] self.load_middleware(), referer: http://malaleche.quijost.com/
[Mon Nov 21 19:36:27 2011] [error] [client XXX.XXX.XXX.XXX] File "/usr/local/lib/python2.7/site-packages/Django-1.3.1-py2.7.egg/django/core/handlers/base.py", line 39, in load_middleware, referer: http://malaleche.quijost.com/
[Mon Nov 21 19:36:27 2011] [error] [client XXX.XXX.XXX.XXX] for middleware_path in settings.MIDDLEWARE_CLASSES:, referer: http://malaleche.quijost.com/
[Mon Nov 21 19:36:27 2011] [error] [client XXX.XXX.XXX.XXX] File "/usr/local/lib/python2.7/site-packages/Django-1.3.1-py2.7.egg/django/utils/functional.py", line 276, in __getattr__, referer: http://malaleche.quijost.com/
[Mon Nov 21 19:36:27 2011] [error] [client XXX.XXX.XXX.XXX] self._setup(), referer: http://malaleche.quijost.com/
[Mon Nov 21 19:36:27 2011] [error] [client XXX.XXX.XXX.XXX] File "/usr/local/lib/python2.7/site-packages/Django-1.3.1-py2.7.egg/django/conf/__init__.py", line 40, in _setup, referer: http://malaleche.quijost.com/
[Mon Nov 21 19:36:27 2011] [error] [client XXX.XXX.XXX.XXX] raise ImportError("Settings cannot be imported, because environment variable %s is undefined." % ENVIRONMENT_VARIABLE), referer: http://malaleche.quijost.com/
Te aconsejo poner:
try:
application = django.core.handlers.wsgi.WSGIHandler()
except Exception, e:
print e
Así podrás capturar cualquier excepción que se lance en tu aplicación sin necesidad de consultar los logs.
Como ves, el propio wsgi, te obliga a definir la variable en algún sitio. Si no quieres ahi, puedes definirla en el __init__.py de tu proyecto, pero debes definir la variable con el archivo antes de inicializar.