After trying several times, without any success, to create a discussion forum with Tal.ki, I tried Nabble only once and succeeded.
Now I have a forum for the wiki I'm going to use with my students this school year- We Play and Learn English Wiki.
I have created two threads: one for students' introductions and one for asking and giving help with posting in the forum.
Creating a forum with Nabble takes less than a minute, it is very easy and free. Embedding is equally easy, you only have to copy and paste the HTML code.
I can't wait to read my students' first posts.
To me the forum looks quite all right as a page of the wiki, but I'd like to hear your opinion, especially if you see something I have missed or could make better.