UPDATE: It's working now. I think the reason for this behaviour was cloudflare caching which I have installed.
This was the original question:
I successfully installed the Q&A plugin but there's one problem. The list of questions at http://www.mysite.com/questions is only visible to logged in users. Single question display at http://www.mysite.com/questions/my-question is visible for all, but the overview list is not.
Here's a screenshot: https://img.skitch.com/20120201-f2gy9rxs1jn34ka45g86y1esbm.png
Any reason for this?
Thanks for your help!