title: Url list problems
body: <p>I have a problem with url patterns, you can see them below.</p>
  
  <p>I can connect to the only one category called "Python" (<code>slug = 'python'</code>). Others like "Django", "Other categories", "Myown" links are not working, they're showing me 404 errors like below.</p>
  
  <pre><code>Page not found (404)
  Request Method: GET
  Request URL:    http://127.0.0.1:8000/rango/category/myown
  Using the URLconf defined in tang_w_djang.urls, Django tried these URL 
  patterns, in this order:
  ^admin/
  ^$ [name='index']
  ^rango/ ^$ [name='index']
  ^rango/ ^about/$ [name='about']
  ^rango/ ^add_category/$ [name='add_category']
  ^rango/ ^category/(?P&lt;category_name_slug&gt;[\w\-]+)/$ [name='show_category']
  ^rango/ ^category/(?P&lt;category_name_slug&gt;[\w\-]+)/add_page/$  [name='add_page']
  The current URL, rango/category/myown, didn't match any of these.
  </code></pre>