Django-registration has not been made compatible with Djagno 1.6. This patch will fix your problem: https://bitbucket.org/ubernostrum/django-registration/pull-request/63/django-16-compatibility-fix-auth-views/diff
registration/auth_urls.py:
urlpatterns = patterns('',
url(r'^login/$',
auth_views.login,
{'template_name': 'registration/login.html'},
name='auth_login'),
url(r'^logout/$',
auth_views.logout,
{'template_name': 'registration/logout.html'},
name='auth_logout'),
url(r'^password/change/$',
auth_views.password_change,
{'post_change_redirect': reverse_lazy('auth_password_change_done')},
name='auth_password_change'),
url(r'^password/change/done/$',
auth_views.password_change_done,
name='auth_password_change_done'),
url(r'^password/reset/$',
auth_views.password_reset,
{'post_reset_redirect': reverse_lazy('auth_password_reset_done')},
name='auth_password_reset'),
url(r'^password/reset/confirm/(?P<uidb64>[0-9A-Za-z_\-]+)/(?P<token>.+)/$',
auth_views.password_reset_confirm,
name='auth_password_reset_confirm'),
url(r'^password/reset/complete/$',
auth_views.password_reset_complete,
{'post_reset_redirect': reverse_lazy('auth_password_reset_complete')},
name='auth_password_reset_complete'),
url(r'^password/reset/done/$',
auth_views.password_reset_done,
name='auth_password_reset_done'),
)