I have subscribed to one of the forums directly as it is probably the one that interests me the most. Safari is still my browser of preference because of its speed over Firefox on my platform. I have found, however, that the Safari RSS reader has picked up on a small bug. Usually when clicking the blue bar at the top, you are meant to go back to the originating site, so I would presume that clicking the blue bar would take me back to http://www.workingwithrails.com/forums/4-ask-a-rails-expert instead it sends me back to http://www.workingwithrails.com/forums/4-ask-a-rails-expert/posts. I think you have to define the over all link for the feed as its just replacing the old safari feed with http.
Hope I've been able to explain myself properly, its not a huge deal or anything, but would be something that I would enjoy having work.
Thanks for you hard work!