Looks like the old deprecated twitter api was finally disabled. (I hadn't followed the API closely, so was not aware). I'm working on the fix.
Truth be told, the whole Twitter support on DKPSystem.com is a cheap hack I did in a rush back whenever I did it. I've been meaning to update the twitter support to be less terrible (@names, #hashtags, and URLs into actual links, add avatars, provide a link back to the original tweet, ya know: all that fun stuff any semi-decent twitter client would support).