A small bug in creating valid URLs from language specific letters (ą, ć, ę, ł, ń, ó, ś, ź, ż). To test it please add "ł" to the topic title. You'll get an URL with just a topic ID (/topic/private/111/#c1).
It should be converted to "L" letter (ł=l) and displayed in the URL like all other additional characters
Okay, it's Django Framework related.
Same bug exists in QSDA:http://jira.osqa.net/browse/OSQA-664
That's right, Django does not provide this out of the box. There seems to be two apps to handle this... unicode-slugify will keep special characters, in most modern browsers this is ok, but I would not bet on it. There's a second app called awesome-slugify which will do what you ask.
I can switch to awesome-slugify, the thing is, it requires a GPL library...