I've updated the forum software with a bookmark functionality. At the bottom of the main section list (the page you see when you enter the forums) You'll find the entry for your bookmarks. You can bookmark any thread you like. Bookmarking a thread is very simple, just click on the yellow star at the top of a thread's message listing (when you view a thread). To unbookmark a thread, either remove it from the list in the bookmark list, or click on the star with the red cross at the top of a bookmarked thread in message view.
I've added this feature because there is no good RSS reader on the market which suited my needs for tracking threads/postings which I had to reply to. I hope this feature is useful to you too. If you have requests for this feature, post in this thread
(I used RSSBandit for this, but I'm fed up with its bugs and although it's open source, the development speed of it is very slow...)