Browsers do not reconnect after restarting Karma server

I'm trying Karma 0.12(.23) with a small test project, but when I restart Karma, the (previously-connected) browsers won't reconnect automatically. Any clue what might be wrong? Example code is on https://github.com/felixrabe-spikes/2014-003-learning-karma

I'm learning Karma with http://www.letscodejavascript.com/v3/comments/live/134#comment-1591305432, and according to James Shore, this is behavior that changed between 0.10 and 0.12. (I've also tried http://stackoverflow.com/a/24807865/1034080.)

If this behavior indeed changed on purpose for 0.12, what is a way to achieve what I try to do?