I enabled Campfire integration, and the review link that it dumps into the chat is formatted as so (my personal URL/repo bits removed): http://[myapp].beanstalkapp.com/u/e45b07b6
Which generates this URL: http://[myapp].beanstalkapp.com/[myrepo]/changesets/preview/17/index.php
Which nets me a 404 page. From within Beanstalk, however, the review link works fine, but is a bit different: http://[myapp].beanstalkapp.com/[myrepo]/browse/trunk/index.php?rev=17
This is the "preview" link available from that browse page: http://[myapp].beanstalkapp.com/[myrepo]/live/trunk/index.php
You can contact me for specific details, but I'm guessing it's not unique to me, and I'm guessing it's something along the lines of routes changing but nobody telling the review link generator.