I have been using the "stable" version for OSX on my up to date system. I have had to reinstall DrJava a ton of times because when I try to launch it, the dock icon just bounces for about a minute and then when queried is "not responding". No idea what to do besides reinstalling.
I recommend using the beta release. No one on the development team has run the stable version recently. In fact, the stable version has not been tested on the latest release of OSX. We will release a new stable release (similar to the current beta release) soon.
You can also try downloading the latest weekly build but it is only available as a jar file rather than an OSX app.
-- Corky