I'm the co-founder of a group blog, and it seems like SU works fine one day, then craps out on us the next. We've integrated an SU button in each of our posts, but it only works sporadically. Sometimes it will work if we switch to the older version of SU, but not always. The most common error is that when someone clicks the SU button, and the following "I Like It" button, they are asked to log in, and when they try to, nothing happens. The most recent error is that someone tries to stumble a post, and just ends up on a blank page with the post not shared.