http://mysite.com/questions/ask/ lead to a 404 error page

Hello, I just installed Q&A and I cannot access the generated page http://www.sharelocaltips.com/questions/ask/

I tried to publish a Question and preview it, but it's the same. It's basically a problem of taxonomy.

I'm using the Directory Theme from Templatic, which is based on their Tevolution plugin and the management of taxonomy is probably a bit complicated in my case... Thank you for your help.