Index: django/utils/translation/trans_real.py
===================================================================
--- django/utils/translation/trans_real.py      (revision 6424)
+++ django/utils/translation/trans_real.py      (working copy)
@@ -338,7 +338,7 @@
         if lang_code in supported and lang_code is not None and check_for_language(lang_code):
             return lang_code
 
-    lang_code = request.COOKIES.get('django_language', None)
+    lang_code = request.COOKIES.get( settings.LANGUAGE_COOKIE_NAME, None)
     if lang_code in supported and lang_code is not None and check_for_language(lang_code):
         return lang_code

Index: django/views/i18n.py
===================================================================
--- django/views/i18n.py        (revision 6424)
+++ django/views/i18n.py        (working copy)
@@ -22,7 +22,7 @@
         if hasattr(request, 'session'):
             request.session['django_language'] = lang_code
         else:
-            response.set_cookie('django_language', lang_code)
+            response.set_cookie(settings.LANGUAGE_COOKIE_NAME, lang_code)
     return response
 
 NullSource = """

Index: django/conf/global_settings.py
===================================================================
--- django/conf/global_settings.py      (revision 6424)
+++ django/conf/global_settings.py      (working copy)
@@ -90,6 +90,12 @@
 # to load the internationalization machinery.
 USE_I18N = True
 
+#
+# Make sure that this is different to to all
+# other cookie names (e.g. SESSION_COOKIE_NAME)
+#
+LANGUAGE_COOKIE_NAME = 'django_language'
+
 # Not-necessarily-technical managers of the site. They get broken link
 # notifications and other various e-mails.
 MANAGERS = ADMINS