This seems to be caused by certain posts, but I have not checked which. When some posts are in the RSS list, it times out loading.
At the moment if you add a limit of 15 to the list you can see the issue, a higher limit will probably guarantee you encounter it. It's been happening more frequently.
http://www.adventuregamestudio.co.uk/forums/index.php?type=rss;action=.xml&limit=15
It is currently failing on a limit=1, which is this post (http://www.adventuregamestudio.co.uk/forums/index.php?topic=56458.msg636595869#msg636595869). Maybe it has something to do with the spoiler tag.
The update seems to have fixed this.
Thanks :)