Rhythmbox 0.8.4 has been released
Among other things, I spent a day squashing memory leaks in Rhythmbox and GStreamer. Upgrading to this release is suggested for long-running playback, and you'll also want to upgrade to the hopefully-soon-to-be-released gstreamer-plugins 0.8.2 (which will also fix stuff like infinite loops on .wma files).Download